MT Mike
NAXJA Forum User
- Location
- Helena, MT
-
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Cruiser's RENIX diagnostics thread
- Thread starter cruiser54
- Start date
MT Mike
NAXJA Forum User
- Location
- Helena, MT
It'll get cleaned up/organized before going to the FAQ section.
cruiser54
NAXJA Forum User
- Location
- Prescott, Az
Re: Cruiser's RENIX TPS Instructions
That is a sensor ground circuit fix which works on vehicles whether they have the C101 or not. On vehicles with the C101, 87 and 88, it does end up bypassing the C101.
I went back into the document to modify it so I could clarify the minor differences of having the C101 vs not having it but the changes wouldn't "stick".
That is a sensor ground circuit fix which works on vehicles whether they have the C101 or not. On vehicles with the C101, 87 and 88, it does end up bypassing the C101.
I went back into the document to modify it so I could clarify the minor differences of having the C101 vs not having it but the changes wouldn't "stick".
Last edited:
MT Mike
NAXJA Forum User
- Location
- Helena, MT
Re: Cruiser's RENIX TPS Instructions
PM me the correct text, and I'll edit the post for you.
PM me the correct text, and I'll edit the post for you.
cruiser54
NAXJA Forum User
- Location
- Prescott, Az
Re: Cruiser's RENIX TPS Instructions
Part of th eproblem is that I go into that document, edit the text, and when I save it, the changes disappear and it goes back to original.
cruiser54
NAXJA Forum User
- Location
- Prescott, Az
Every write-up has been revised and given a revision date. I also added one on the instrument panel ground upgrade. Read it here and comment please.
Improving the Instrument Panel Ground
The ground point for the complete instrument cluster on your XJ or MJ is located up under the driver’s side dash. If you lay on your back and look up under there with a flashlight, without wearing a hat, you will see a black wire attached to a shiny piece of metal almost directly above the hood release knob. The screw will have either a ¼" or 5/16" head on it.
This ground point is responsible for handling the ground circuit for the following items: Dome lamps, Seatbelt and key warning, trans comfort switch, wiper switch, headlamp switch and delay module, fog lamp switch, cargo lamp switch, all instrument panel grounds and illumination, power windows and door locks, cruise control dump valve, and a few more things.
The problem is that where the ground point is located does not have a good contact with the chassis where the ground should be. The solution is simple.
Make up a jumper wire with #10 gauge wire about 10" long. On one end, crimp on a ¼" round wire terminal. On the other end, crimp on a 3/8" round wire terminal.
Remove the screw from the existing ground wire and attach the small terminal of your jumper so that the original wire and your new jumper share the same attaching point, one over the other.
Look above the driver’s side plastic kick panel just forward of the top of the hood release knob. You will see an 8mm stud there. Attach the large terminal end there with a washer and nut over it tightened securely.
**Special note for Comanche owners: Make your jumper wire 12" long and attach it on the driver’s side kick panel close to the fusebox on the 8mm stud.**
Revised 11-28-2011
Improving the Instrument Panel Ground
The ground point for the complete instrument cluster on your XJ or MJ is located up under the driver’s side dash. If you lay on your back and look up under there with a flashlight, without wearing a hat, you will see a black wire attached to a shiny piece of metal almost directly above the hood release knob. The screw will have either a ¼" or 5/16" head on it.
This ground point is responsible for handling the ground circuit for the following items: Dome lamps, Seatbelt and key warning, trans comfort switch, wiper switch, headlamp switch and delay module, fog lamp switch, cargo lamp switch, all instrument panel grounds and illumination, power windows and door locks, cruise control dump valve, and a few more things.
The problem is that where the ground point is located does not have a good contact with the chassis where the ground should be. The solution is simple.
Make up a jumper wire with #10 gauge wire about 10" long. On one end, crimp on a ¼" round wire terminal. On the other end, crimp on a 3/8" round wire terminal.
Remove the screw from the existing ground wire and attach the small terminal of your jumper so that the original wire and your new jumper share the same attaching point, one over the other.
Look above the driver’s side plastic kick panel just forward of the top of the hood release knob. You will see an 8mm stud there. Attach the large terminal end there with a washer and nut over it tightened securely.
**Special note for Comanche owners: Make your jumper wire 12" long and attach it on the driver’s side kick panel close to the fusebox on the 8mm stud.**
Revised 11-28-2011
cruiser54
NAXJA Forum User
- Location
- Prescott, Az
Revised and added write-ups
Cruiser’s Headlight Upgrade Harness Instructions
Absolutely plug and play. Remove grille and headlamp bulbs. I fed my harnesses from the passenger side starting between the battery and the back of the headlamp housing, over to the driver side. Plug the driver side bulb into the new harness. Attach the new harness's ground wire under one of the small bolts on the radiator support after scraping the paint off under it. Attach the harness to the existing harness behind the grille working toward the passenger side. . Plug the new harness plug into passenger headlamp. Plug original headlamp plug into receptacle on new harness. Attach the ground for the passenger side just like you did the driver side under a radiator support bolt. Attach relays with provided bracket on the passenger side inner fender. Connect power wires to battery.
Improving the Instrument Panel Ground
The ground point for the complete instrument cluster on your XJ or MJ is located up under the driver’s side dash. If you lay on your back and look up under there with a flashlight, without wearing a hat, you will see a black wire attached to a shiny piece of metal almost directly above the hood release knob. The screw will have either a ¼" or 5/16" head on it.
This ground point is responsible for handling the ground circuit for the following items: Dome lamps, Seatbelt and key warning, trans comfort switch, wiper switch, headlamp switch and delay module, fog lamp switch, cargo lamp switch, all instrument panel grounds and illumination, power windows and door locks, cruise control dump valve, and a few more things.
The problem is that where the ground point is located does not have a good contact with the chassis where the ground should be. The solution is simple.
Make up a jumper wire with #10 gauge wire about 10" long. On one end, crimp on a ¼" round wire terminal. On the other end, crimp on a 3/8" round wire terminal.
Remove the screw from the existing ground wire and attach the small terminal of your jumper so that the original wire and your new jumper share the same attaching point, one over the other.
Look above the driver’s side plastic kick panel just forward of the top of the hood release knob. You will see an 8mm stud there. Attach the large terminal end there with a washer and nut over it tightened securely.
**Special note for Comanche owners: Make your jumper wire 12" long and attach it on the driver’s side kick panel close to the fusebox on the 8mm stud.**
Revised 11-28-2011
Renix CPS Testing and Adjusting
Renix CPSs have to put out a strong enough signal to the ECU so that it will provide spark.
Most tests for the CPS suggest checking it for an ohms value. This is unreliable and can cause some wasted time and aggravation in your diagnosis of a no-start issue as the CPS will test good when in fact it is bad.
The problem with the ohms test is you can have the correct amount of resistance through the CPS but it isn’t generating enough voltage to trigger the ECU to provide spark.
Unplug the harness connector from the CPS. Using your voltmeter set on AC volts and probing both wires in the connector going to the CPS, crank the engine over. It won’t start with the CPS disconnected.
You should get a reading of .5 AC volts.
If you are down in the .35 AC volts range or lower on your meter reading, you can have intermittent crank/no-start conditions from your Renix Jeep. Some NEW CPSs (from the big box parts stores) have registered only .2 AC volts while reading the proper resistance!! That’s a definite no-start condition. Best to buy your CPS from Napa or the dealer.
Sometimes on a manual transmission equipped Renix Jeep there is an accumulation of debris on the tip of the CPS. It’s worn off clutch material and since the CPS is a magnet, the metal sticks to the tip of the CPS causing a reduced voltage signal. You MAY get by with cleaning the tip of the CPS off.
A little trick for increasing the output of your CPS is to drill out it’s mounting holes with the first drill bit that just won’t fit through the original holes. Then, when mounting it, hold the CPS down as close to the flywheel as you can while tightening the bolts.
Revised 11-28-2011
Renix Ground Refreshing
The Renix era XJs and MJs were built with an under-engineered grounding system for the engine/transmission electronics. One problem in particular involves the multiple ground connection at the engine dipstick tube stud. A poor ground here can cause a multitude of driveabililty issues, wasted time, and wasted money replacing unnecessary components.
The components grounding at the dipstick tube stud are:
Distributor Sync Sensor, TCU main ground, TCU "Shift Point Logic", Ignition control Module, Injectors, ECU main ground which other engine sensors ground through, Oxygen sensor, Knock Sensor, Cruise Control, and Transmission Sync signal. All extremely important stuff.
The factory was aware of the issues with this ground point and addressed it by suggesting the following:
Remove the nut holding the wire terminals to the stud. Verify that the stud is indeed tightened securely into the block. Scrape any and all paint from the stud’s mounting surface where the wires will attach. Must be clean, shiny and free of any oil, grease, or paint.
Inspect the wire terminals. Check to see that none of the terminals are crimped over wire insulation instead of bare wire. Be sure the crimps are tight. It wouldn’t hurt to re-crimp them just as a matter of course. Sand and polish the wire terminals until clean and shiny on both sides. Reinstall all the wires to the stud and tighten the nut down securely.
While you’re in that general area, locate the battery negative cable which is fastened to the engine block just forward of the dipstick stud. Remove the bolt, scrape the block to bare metal, clean and polish the cable terminal, and reattach securely.
Another area where the grounding system on Renix era Jeeps was lacking is the engine to chassis ground. There is a braided cable from the back of the cylinder head that also attaches to the driver’s side of the firewall. This cable is undersized for it’s intended use and subject to corrosion and poor connections at each end.
First off, remove the cable end from the firewall using a 15mm wrench or socket. Scrape the paint off down to bare metal and clean the wire terminal. Reattach securely.
Remove the other end of the cable from the rear of the head using a 3’4" socket. Clean all the oil, paint and crud from the stud. Clean the wire terminal of the cable and reattach securely.
A suggestion regarding the braided cable:
I prefer to add a #4 Gauge cable from the firewall to a bolt on the rear of the intake manifold, either to a heat shield bolt or fuel rail bolt. A cable about 18" long with a 3/8" lug on each end works great and you can get one at any parts store already made up. Napa has them as part number 781116.
A further improvement to the grounding system can be made using a #4 cable, about 10" long with 3/8" terminals at each end. Attach one end of this cable to the negative battery bolt and the other end under the closest 10mm headed bolt on the radiator support just forward of the battery. Napa part number 781115.
If you want to upgrade your grounds and battery cables in general, contact Jon at www.kelleyswip.com. He makes an incredible cable upgrade for a very reasonable price.
Revised 11-28-2011
Renix Jeep C101 Connector Refreshing
The C101 connector on 1987 and 1988 Renix Jeeps was a source of electrical resistance when the vehicles were new. So much so that the factory eliminated this connector in the 1989 and 1990 models. The factory recommended cleaning this connector to insure the proper voltage and ground signals between the ECU and the fuel injection sensors. We can only imagine how this connector has become a larger source of voltage loss and increased resistance over a period of almost 25 years. The C101 connector needs to be cleaned at least once in the lifetime of your vehicle. Chances are it’s never been done before.
Almost every critical signal between the engine sensors, injectors, and the ECU travel the path through the C101.
The C101 is located on the driver’s side firewall above and behind the brake booster. It is held together with a single bolt in it’s center. To get the connectors apart, simply remove the bolt and pull the halves apart. You will find the connector is packed with a black tar like substance which has hardened over time.
Take a pocket screwdriver or the like and scrape out all the tar crap you can. Follow up by spraying out both connector halves with brake cleaner and then swabbing out the remainder of the tar. Repeat this procedure until the tar is totally removed. This may require 3 or more repetitions. Wipe out the connectors after spraying with a soft cloth.
If you have a small pick or dental tool tweak the female connectors on the one side so they grab the pins on the opposite side a bit tighter. Apply a true dielectric grease, not the stuff that came with your brake pads, to the connection and bolt it back together.
Revised 11-28-2011
Renix Jeep ICU/Coil contact refreshing
The contacts between the coil and the ICU on your Renix Jeep can become corroded and loose causing a complete or intermittent no-start condition. I recommend the following procedure as a maintenance precaution to insure this is eliminated as a possible cause now and in the future.
The coil is attached to the ICU by two T20 Torx bolts. Remove these two bolts and lift the coil up off the ICU. You will see 2 pins and 2 sets of contacts. Clean both the pins and springy contact pieces with a good electronics cleaner.
Squeeze the springy contacts closer together with some needlenose pliers. Apply some dielectric grease to the contacts and bolt the coil back on to the ICU.
While you’re right there unplug the connectors from the ICU and inspect the pins in the harness connector. Make sure the pins are not retracted into the connector. Spray out the connector and the receptacle of the ICU with the same good electronics cleaner you used earlier. Apply dielectric grease to the connectors and plug them back in.
I feel this procedure should be performed at least once in the lifetime of a Renix Jeep.
Revised 11-28-2011
Find your Intake Air Temp sensor. It's the sensor just to the rear of the throttle body, has 2 wires, and screws into the intake manifold.
Where it's connector plugs into the harness you will see that one of the wires on the harness side is brown with a white stripe. Follow the brown with white strip wire back into the harness. You'll have to open up the split-loom plastic sheathing to follow it. It will come to a splice with 2 other brown with white wires. They're from the TPS and the CTS. The 3 wires will be spliced to a single wire headed toward the C101 connector if you have an 87 or 88. If you have an 89 or 90, you do not have the C101 bulkhead connector.
Now go to the MAP sensor. Follow the brown with white wire into the harness from there. You will find a splice with 2 more brown with white wires. At the splice you will find the 3 wires connected to a single brown with white wire going toward the C101, or just along the firewall towards the engine if you have an 89 or 90. Along with the MAP sensor that you traced, they are the ECU sensor ground port and the diagnostic connector on the passenger inner fender.
You now have 2 sets of 3 brown with white wires, one near the firewall and one near the engine.
Cut the splices out of each set of wires. Bring both sets of 3 wires together. You will be connecting the 2 sets of three wires together. Solder the 2 sets of wires together and insulate them properly with tape or shrink tubing.
Zip-tie up your new sensor loom to allow for engine movement. I prefer to cover it with some new split-loom or wrap it neatly with electrical tape when done.
RENIX TPS ADJUSTMENT
Before attempting to adjust your TPS be sure the throttle body has been recently
cleaned.
It's especially important that the edges of the throttle butterfly are free of any
carbon build-up.
IMPORTANT NOTE: Using the positive (red) lead of your ohmmeter, probe the B
terminal of the flat 3 wire connector
of the TPS . The letters are embossed on the connector itself.
Touch the black lead of your meter to the negative battery post.
If you see more than 1 ohm of resistance some modifications to the sensor ground
harness will be
necessary. The harness repair must be performed before proceeding.
I can provide an instruction sheet for that if needed.
MANUAL TRANSMISSION:
RENIX manual transmission equipped XJs have a three-wire TPS mounted on the
throttle body.
This manual transmission vehicle TPS provides data input to the ECU. The manual
transmission
TPS has three wires in the connector and they're clearly embossed with the letters
A,B, and C.
Wire "A" is positive.
Wire "B" is ground.
Key ON, measure voltage from "A" positive to "B" ground by back-probing the
connectors..
Note the voltage reading--this is your REFERENCE voltage.
Key ON, back-probe the connector at wires "B" and "C". Measure the voltage. This
is your
OUTPUT voltage.
Your OUTPUT voltage needs to be seventeen percent of your REFERENCE voltage.
For
example: 4.82 volts X .17=.82 volts. Adjust the TPS until you have achieved this
percentage. If
you can't achieve the correct output voltage replace the TPS and start over.
AUTOMATIC TRANSMISSION:
RENIX automatic transmission equipped XJs have a TPS with two connectors. There
is a flat three-
wire connector, same as the manual transmission vehicles have, and it is tested the
same as the
manual transmission equipped vehicles--FOR ENGINE MANAGEMENT RELATED
ISSUES.
However, the automatic TPS also has a square four-wire connector clearly
embossed with the letters
A,B,C, and D. It only uses three wires and provides information to the Transmission
Control Module.
Key ON, measure voltage between "A" positive and "D" ground. Note the voltage.
This is your
REFERENCE voltage.
Back-probe the connector at wires "B" and "D". Measure the voltage. This is your
OUTPUT
voltage. Your OUTPUT voltage needs to be eighty-three percent of your
REFERENCE voltage.
For example 4.8 volts X .83=3.98 volts. Adjust the TPS until you have achieved
this percentage.
If you can't, replace the TPS and start over.
So, if you have an automatic equipped XJ your TPS has two sides--one side feeds
the ECU, and
the other side feeds the TCU. If you have TRANSMISSION issues check the
four-wire
connector side of the TPS. If you have ENGINE issues check the three-wire
connector side of
the TPS.
For those with a MANUAL TRANSMISSION--the TPS for the manual transmission
XJs is
stupid expensive. You can substitute the automatic transmission TPS which is
reasonably priced.
Revised 11-28-2001
Cruiser’s Headlight Upgrade Harness Instructions
Absolutely plug and play. Remove grille and headlamp bulbs. I fed my harnesses from the passenger side starting between the battery and the back of the headlamp housing, over to the driver side. Plug the driver side bulb into the new harness. Attach the new harness's ground wire under one of the small bolts on the radiator support after scraping the paint off under it. Attach the harness to the existing harness behind the grille working toward the passenger side. . Plug the new harness plug into passenger headlamp. Plug original headlamp plug into receptacle on new harness. Attach the ground for the passenger side just like you did the driver side under a radiator support bolt. Attach relays with provided bracket on the passenger side inner fender. Connect power wires to battery.
Improving the Instrument Panel Ground
The ground point for the complete instrument cluster on your XJ or MJ is located up under the driver’s side dash. If you lay on your back and look up under there with a flashlight, without wearing a hat, you will see a black wire attached to a shiny piece of metal almost directly above the hood release knob. The screw will have either a ¼" or 5/16" head on it.
This ground point is responsible for handling the ground circuit for the following items: Dome lamps, Seatbelt and key warning, trans comfort switch, wiper switch, headlamp switch and delay module, fog lamp switch, cargo lamp switch, all instrument panel grounds and illumination, power windows and door locks, cruise control dump valve, and a few more things.
The problem is that where the ground point is located does not have a good contact with the chassis where the ground should be. The solution is simple.
Make up a jumper wire with #10 gauge wire about 10" long. On one end, crimp on a ¼" round wire terminal. On the other end, crimp on a 3/8" round wire terminal.
Remove the screw from the existing ground wire and attach the small terminal of your jumper so that the original wire and your new jumper share the same attaching point, one over the other.
Look above the driver’s side plastic kick panel just forward of the top of the hood release knob. You will see an 8mm stud there. Attach the large terminal end there with a washer and nut over it tightened securely.
**Special note for Comanche owners: Make your jumper wire 12" long and attach it on the driver’s side kick panel close to the fusebox on the 8mm stud.**
Revised 11-28-2011
Renix CPS Testing and Adjusting
Renix CPSs have to put out a strong enough signal to the ECU so that it will provide spark.
Most tests for the CPS suggest checking it for an ohms value. This is unreliable and can cause some wasted time and aggravation in your diagnosis of a no-start issue as the CPS will test good when in fact it is bad.
The problem with the ohms test is you can have the correct amount of resistance through the CPS but it isn’t generating enough voltage to trigger the ECU to provide spark.
Unplug the harness connector from the CPS. Using your voltmeter set on AC volts and probing both wires in the connector going to the CPS, crank the engine over. It won’t start with the CPS disconnected.
You should get a reading of .5 AC volts.
If you are down in the .35 AC volts range or lower on your meter reading, you can have intermittent crank/no-start conditions from your Renix Jeep. Some NEW CPSs (from the big box parts stores) have registered only .2 AC volts while reading the proper resistance!! That’s a definite no-start condition. Best to buy your CPS from Napa or the dealer.
Sometimes on a manual transmission equipped Renix Jeep there is an accumulation of debris on the tip of the CPS. It’s worn off clutch material and since the CPS is a magnet, the metal sticks to the tip of the CPS causing a reduced voltage signal. You MAY get by with cleaning the tip of the CPS off.
A little trick for increasing the output of your CPS is to drill out it’s mounting holes with the first drill bit that just won’t fit through the original holes. Then, when mounting it, hold the CPS down as close to the flywheel as you can while tightening the bolts.
Revised 11-28-2011
Renix Ground Refreshing
The Renix era XJs and MJs were built with an under-engineered grounding system for the engine/transmission electronics. One problem in particular involves the multiple ground connection at the engine dipstick tube stud. A poor ground here can cause a multitude of driveabililty issues, wasted time, and wasted money replacing unnecessary components.
The components grounding at the dipstick tube stud are:
Distributor Sync Sensor, TCU main ground, TCU "Shift Point Logic", Ignition control Module, Injectors, ECU main ground which other engine sensors ground through, Oxygen sensor, Knock Sensor, Cruise Control, and Transmission Sync signal. All extremely important stuff.
The factory was aware of the issues with this ground point and addressed it by suggesting the following:
Remove the nut holding the wire terminals to the stud. Verify that the stud is indeed tightened securely into the block. Scrape any and all paint from the stud’s mounting surface where the wires will attach. Must be clean, shiny and free of any oil, grease, or paint.
Inspect the wire terminals. Check to see that none of the terminals are crimped over wire insulation instead of bare wire. Be sure the crimps are tight. It wouldn’t hurt to re-crimp them just as a matter of course. Sand and polish the wire terminals until clean and shiny on both sides. Reinstall all the wires to the stud and tighten the nut down securely.
While you’re in that general area, locate the battery negative cable which is fastened to the engine block just forward of the dipstick stud. Remove the bolt, scrape the block to bare metal, clean and polish the cable terminal, and reattach securely.
Another area where the grounding system on Renix era Jeeps was lacking is the engine to chassis ground. There is a braided cable from the back of the cylinder head that also attaches to the driver’s side of the firewall. This cable is undersized for it’s intended use and subject to corrosion and poor connections at each end.
First off, remove the cable end from the firewall using a 15mm wrench or socket. Scrape the paint off down to bare metal and clean the wire terminal. Reattach securely.
Remove the other end of the cable from the rear of the head using a 3’4" socket. Clean all the oil, paint and crud from the stud. Clean the wire terminal of the cable and reattach securely.
A suggestion regarding the braided cable:
I prefer to add a #4 Gauge cable from the firewall to a bolt on the rear of the intake manifold, either to a heat shield bolt or fuel rail bolt. A cable about 18" long with a 3/8" lug on each end works great and you can get one at any parts store already made up. Napa has them as part number 781116.
A further improvement to the grounding system can be made using a #4 cable, about 10" long with 3/8" terminals at each end. Attach one end of this cable to the negative battery bolt and the other end under the closest 10mm headed bolt on the radiator support just forward of the battery. Napa part number 781115.
If you want to upgrade your grounds and battery cables in general, contact Jon at www.kelleyswip.com. He makes an incredible cable upgrade for a very reasonable price.
Revised 11-28-2011
Renix Jeep C101 Connector Refreshing
The C101 connector on 1987 and 1988 Renix Jeeps was a source of electrical resistance when the vehicles were new. So much so that the factory eliminated this connector in the 1989 and 1990 models. The factory recommended cleaning this connector to insure the proper voltage and ground signals between the ECU and the fuel injection sensors. We can only imagine how this connector has become a larger source of voltage loss and increased resistance over a period of almost 25 years. The C101 connector needs to be cleaned at least once in the lifetime of your vehicle. Chances are it’s never been done before.
Almost every critical signal between the engine sensors, injectors, and the ECU travel the path through the C101.
The C101 is located on the driver’s side firewall above and behind the brake booster. It is held together with a single bolt in it’s center. To get the connectors apart, simply remove the bolt and pull the halves apart. You will find the connector is packed with a black tar like substance which has hardened over time.
Take a pocket screwdriver or the like and scrape out all the tar crap you can. Follow up by spraying out both connector halves with brake cleaner and then swabbing out the remainder of the tar. Repeat this procedure until the tar is totally removed. This may require 3 or more repetitions. Wipe out the connectors after spraying with a soft cloth.
If you have a small pick or dental tool tweak the female connectors on the one side so they grab the pins on the opposite side a bit tighter. Apply a true dielectric grease, not the stuff that came with your brake pads, to the connection and bolt it back together.
Revised 11-28-2011
Renix Jeep ICU/Coil contact refreshing
The contacts between the coil and the ICU on your Renix Jeep can become corroded and loose causing a complete or intermittent no-start condition. I recommend the following procedure as a maintenance precaution to insure this is eliminated as a possible cause now and in the future.
The coil is attached to the ICU by two T20 Torx bolts. Remove these two bolts and lift the coil up off the ICU. You will see 2 pins and 2 sets of contacts. Clean both the pins and springy contact pieces with a good electronics cleaner.
Squeeze the springy contacts closer together with some needlenose pliers. Apply some dielectric grease to the contacts and bolt the coil back on to the ICU.
While you’re right there unplug the connectors from the ICU and inspect the pins in the harness connector. Make sure the pins are not retracted into the connector. Spray out the connector and the receptacle of the ICU with the same good electronics cleaner you used earlier. Apply dielectric grease to the connectors and plug them back in.
I feel this procedure should be performed at least once in the lifetime of a Renix Jeep.
Revised 11-28-2011
Find your Intake Air Temp sensor. It's the sensor just to the rear of the throttle body, has 2 wires, and screws into the intake manifold.
Where it's connector plugs into the harness you will see that one of the wires on the harness side is brown with a white stripe. Follow the brown with white strip wire back into the harness. You'll have to open up the split-loom plastic sheathing to follow it. It will come to a splice with 2 other brown with white wires. They're from the TPS and the CTS. The 3 wires will be spliced to a single wire headed toward the C101 connector if you have an 87 or 88. If you have an 89 or 90, you do not have the C101 bulkhead connector.
Now go to the MAP sensor. Follow the brown with white wire into the harness from there. You will find a splice with 2 more brown with white wires. At the splice you will find the 3 wires connected to a single brown with white wire going toward the C101, or just along the firewall towards the engine if you have an 89 or 90. Along with the MAP sensor that you traced, they are the ECU sensor ground port and the diagnostic connector on the passenger inner fender.
You now have 2 sets of 3 brown with white wires, one near the firewall and one near the engine.
Cut the splices out of each set of wires. Bring both sets of 3 wires together. You will be connecting the 2 sets of three wires together. Solder the 2 sets of wires together and insulate them properly with tape or shrink tubing.
Zip-tie up your new sensor loom to allow for engine movement. I prefer to cover it with some new split-loom or wrap it neatly with electrical tape when done.
RENIX TPS ADJUSTMENT
Before attempting to adjust your TPS be sure the throttle body has been recently
cleaned.
It's especially important that the edges of the throttle butterfly are free of any
carbon build-up.
IMPORTANT NOTE: Using the positive (red) lead of your ohmmeter, probe the B
terminal of the flat 3 wire connector
of the TPS . The letters are embossed on the connector itself.
Touch the black lead of your meter to the negative battery post.
If you see more than 1 ohm of resistance some modifications to the sensor ground
harness will be
necessary. The harness repair must be performed before proceeding.
I can provide an instruction sheet for that if needed.
MANUAL TRANSMISSION:
RENIX manual transmission equipped XJs have a three-wire TPS mounted on the
throttle body.
This manual transmission vehicle TPS provides data input to the ECU. The manual
transmission
TPS has three wires in the connector and they're clearly embossed with the letters
A,B, and C.
Wire "A" is positive.
Wire "B" is ground.
Key ON, measure voltage from "A" positive to "B" ground by back-probing the
connectors..
Note the voltage reading--this is your REFERENCE voltage.
Key ON, back-probe the connector at wires "B" and "C". Measure the voltage. This
is your
OUTPUT voltage.
Your OUTPUT voltage needs to be seventeen percent of your REFERENCE voltage.
For
example: 4.82 volts X .17=.82 volts. Adjust the TPS until you have achieved this
percentage. If
you can't achieve the correct output voltage replace the TPS and start over.
AUTOMATIC TRANSMISSION:
RENIX automatic transmission equipped XJs have a TPS with two connectors. There
is a flat three-
wire connector, same as the manual transmission vehicles have, and it is tested the
same as the
manual transmission equipped vehicles--FOR ENGINE MANAGEMENT RELATED
ISSUES.
However, the automatic TPS also has a square four-wire connector clearly
embossed with the letters
A,B,C, and D. It only uses three wires and provides information to the Transmission
Control Module.
Key ON, measure voltage between "A" positive and "D" ground. Note the voltage.
This is your
REFERENCE voltage.
Back-probe the connector at wires "B" and "D". Measure the voltage. This is your
OUTPUT
voltage. Your OUTPUT voltage needs to be eighty-three percent of your
REFERENCE voltage.
For example 4.8 volts X .83=3.98 volts. Adjust the TPS until you have achieved
this percentage.
If you can't, replace the TPS and start over.
So, if you have an automatic equipped XJ your TPS has two sides--one side feeds
the ECU, and
the other side feeds the TCU. If you have TRANSMISSION issues check the
four-wire
connector side of the TPS. If you have ENGINE issues check the three-wire
connector side of
the TPS.
For those with a MANUAL TRANSMISSION--the TPS for the manual transmission
XJs is
stupid expensive. You can substitute the automatic transmission TPS which is
reasonably priced.
Revised 11-28-2001
Re: Cruiser's RENIX TPS Instructions
You can use a few thicknesses of masking tape to be sure that you get the clearance. When you start it the flywheel will grind/pull the tape off.
Even if it doesn't the tape doesn't interfere with the hall effect of the sensor.
speaking from experience of blipping the starter and hearing a noise and trashing a CPS sensor.
If doing this you must be certain that the CPS does not contact the flywheel or it will destroy the CPS.
You can use a few thicknesses of masking tape to be sure that you get the clearance. When you start it the flywheel will grind/pull the tape off.
Even if it doesn't the tape doesn't interfere with the hall effect of the sensor.
speaking from experience of blipping the starter and hearing a noise and trashing a CPS sensor.
cruiser54
NAXJA Forum User
- Location
- Prescott, Az
How big did you drill the holes?
I didn't. they were just that sloppy.
which is why I didn't give it a second thought when I installed it to put it all the way into the hole.
"they can't be that far off can they?"
why yes, they can be.
cruiser54
NAXJA Forum User
- Location
- Prescott, Az
Did you have the proper shouldered bolts?
- Location
- MilkyWay Galaxy
That is a very good question, as with the shoulder bolts, it looked like I could not drill the over sized holes in the CPS too big, and still have any metal left on the CPS for the bolt head to clamp down on, on mine. I did my second one on the 87, while I was swapping the AW4 out, and the stock position looked like it had a huge 3/16" gap using the OEM shoulder bolts, so I moved it 1/16" closer and still had a huge 1/8" gap or so left.
But non shoulder bolts plus a bigger hole (two drill sizes larger than the OEM) than what I drilled might be just enough to make contact.
cruiser54
NAXJA Forum User
- Location
- Prescott, Az
My thoughts exactly as I have never had a problem drilling the holes out using the stock bolts
cruiser54
NAXJA Forum User
- Location
- Prescott, Az
I think we have an answer!!! They are special shouldered bolts, not easily found by hackers changing trannies. Ecomike has seen and documented the spacing from a CPS to the flywheel. 87manche, you had me scared for a minute as I never had an issue with enlarging the holes.
- Location
- MilkyWay Galaxy
I wonder if the manual Tranny mounting for the CPS is closer the flywheel, than AW4 flex plates? Are all your's manuals?
cruiser54
NAXJA Forum User
- Location
- Prescott, Az
Mine are all autos. The bolts are indeed special.
Squirrel
NAXJA Forum User
- Location
- Centennial
Re: Cruiser's RENIX TPS Instructions
I'm trying to figure this one out as well, so you are essentially connecting all the ground wires from these connectors together, are you connecting them to the wires going through the firewall as well? I have an '89 without the c-101 connector.
I'm trying to figure this one out as well, so you are essentially connecting all the ground wires from these connectors together, are you connecting them to the wires going through the firewall as well? I have an '89 without the c-101 connector.
cruiser54
NAXJA Forum User
- Location
- Prescott, Az
Find your Intake Air Temp sensor. It's the sensor just to the rear of the throttle body, has 2 wires, and screws into the intake manifold.
Where it's connector plugs into the harness you will see that one of the wires on the harness side is brown with a white stripe. Follow the brown with white strip wire back into the harness. You'll have to open up the split-loom plastic sheathing to follow it. It will come to a splice with 2 other brown with white wires. They're from the TPS and the CTS. The 3 wires will be spliced to a single wire headed toward the C101 connector if you have an 87 or 88. If you have an 89 or 90, you do not have the C101 bulkhead connector.
Now go to the MAP sensor. Follow the brown with white wire into the harness from there. You will find a splice with 2 more brown with white wires. At the splice you will find the 3 wires connected to a single brown with white wire going toward the C101, or just along the firewall towards the engine if you have an 89 or 90. Along with the MAP sensor that you traced, they are the ECU sensor ground port and the diagnostic connector on the passenger inner fender.
You now have 2 sets of 3 brown with white wires, one near the firewall and one near the engine.
Cut the splices out of each set of wires eliminating not only the crappy factory splices, but also the single wire between them. Bring both sets of 3 wires together. Solder the 2 sets of wires together and insulate them properly with tape or shrink tubing.
Zip-tie up your new sensor loom to allow for engine movement. I prefer to cover it with some new split-loom or wrap it neatly with electrical tape when done.
Revised 12-02-2011
Where it's connector plugs into the harness you will see that one of the wires on the harness side is brown with a white stripe. Follow the brown with white strip wire back into the harness. You'll have to open up the split-loom plastic sheathing to follow it. It will come to a splice with 2 other brown with white wires. They're from the TPS and the CTS. The 3 wires will be spliced to a single wire headed toward the C101 connector if you have an 87 or 88. If you have an 89 or 90, you do not have the C101 bulkhead connector.
Now go to the MAP sensor. Follow the brown with white wire into the harness from there. You will find a splice with 2 more brown with white wires. At the splice you will find the 3 wires connected to a single brown with white wire going toward the C101, or just along the firewall towards the engine if you have an 89 or 90. Along with the MAP sensor that you traced, they are the ECU sensor ground port and the diagnostic connector on the passenger inner fender.
You now have 2 sets of 3 brown with white wires, one near the firewall and one near the engine.
Cut the splices out of each set of wires eliminating not only the crappy factory splices, but also the single wire between them. Bring both sets of 3 wires together. Solder the 2 sets of wires together and insulate them properly with tape or shrink tubing.
Zip-tie up your new sensor loom to allow for engine movement. I prefer to cover it with some new split-loom or wrap it neatly with electrical tape when done.
Revised 12-02-2011
Awesome stuff 
Glad someone has taken the time to type and share all the good Renix info......
Also adding my 2 cents on CPS adjustment, closer you can get reading to 1.0 volt AC the better while cranking without sensor rubbing the better, as outside temps drop,engine will crank slower and the output CPS voltage will be lower then when its warm....
And for Renix Jeeps that fail emissions after the slew of sensors and O2 replacements few tips..... running fuel pressure cannot be over spec even by a few pounds, triple check the vac line to pressure regulator, check vac line to MAP also.... if your Jeep wont go into closed loop even when coolant and Intake temp are nice and warm , heater voltage to O2 is good, ground is good, 5 volt reference from PCM is good and everything else has been tried I added a MAP sensor enhancer as they call it...... as time goes on the engine vacuum the PCM see's is low enough at idle to cause the PCM to stay in open loop from normal engine wear.... 16.1 inches of vacuum or less will cause this from what I discovered...... so the map enhancer is a cheap and easy way to get the O2 sensor to stay in closed loop.... I can make the PCM see 18.7 inches of vacuum at idle and it stays in closed loop all running conditions and rpm's...It makes the PCM see more engine vaccum which makes it lean..My recent emissions test went from 897 HC and 9.50 CO to 22 HC and .20 CO after I added the enhancer..... Map enhancer is last resort after you have checked all sensors and grounds....... 99% of the time a new O2 sensor will fix the open loop syndrome..... I have a DRB for the Renix and have worked at the dealer for many years in the Renix hey day on Monaco's, Premier's, Alliances and Jeeps........Silicone in the fuel will destroy the O2 sensor which I thought might be my problem, also I was pondering my exhaust temp was dropping below 850 degrees at the O2 sensor.... I tried 3 new o2 sensors I had stashed away and they all acted the same way.... fire it up, warm it up, all good for about 5 minutes, watch the o2 sensor go into closed loop on the DRB, coolant temp 210, IAT/ACT 165, sync working everything working like it should, even had a test light on the heater feed to o2 sensor and watched it..... increase RPM and let idle and o2 goes to .2 volts...sits their for a bit....then bang...open loop 4.97 volts........I pulled my hair out for days cleaning connections and stuff....All I know the MAP might be ioff calibration just a bit, Baro side reads right, just hate tossing 50 bucks for a map and it wasn't the problem.... Map enhancer cost me 14 bucks and saved me allot of money in TUMS
So with people without a DRB you can check to see if your o2 sensor is working with an Analog voltmeter that ranges 0 to 5 volts DC, tap one end into 5 volt reference to PCM at the O2 and the other to a good ground...... needle will move from almost zero to around 4.7 volts, back and fourth...you know its working..... use same method to set your map enhancer.... turn map enhancer clockwise in small steps and watch analog meter hooked to O2 sensor, when you can get the needle to move it's range at all rpm's and revving it up and letting idle then you have enhancer adjusted right...... I cannot tell you actual map voltage as I never hooked a volt meter to it while running and playing around with the enhancer...all set watching info on the DRB........
Okay, done blabbing..... Just wanted to share my emissions adventure on my 1990 Jeep thats been giving me hell since I moved into town and had to do emissions last 2 years...........
Also the map enhancer will increase gas mileage as you are making the PCM use a different set of fuel and ignition mapping based on MAP sensor reading...just dont go to lean, you can actually turn the enhancer up to much and the engine will run hot and stall.......
I only made the single mode enhancer, but i am going to make the dual mode enhancer so can flip switch from city to highway settings......
http://www.fuelsaver-mpg.com/simple-map-maf-enhancer
And again, thanks Cruiser for all the awesome info you took the time to share:clap:
Glad someone has taken the time to type and share all the good Renix info......
Also adding my 2 cents on CPS adjustment, closer you can get reading to 1.0 volt AC the better while cranking without sensor rubbing the better, as outside temps drop,engine will crank slower and the output CPS voltage will be lower then when its warm....
And for Renix Jeeps that fail emissions after the slew of sensors and O2 replacements few tips..... running fuel pressure cannot be over spec even by a few pounds, triple check the vac line to pressure regulator, check vac line to MAP also.... if your Jeep wont go into closed loop even when coolant and Intake temp are nice and warm , heater voltage to O2 is good, ground is good, 5 volt reference from PCM is good and everything else has been tried I added a MAP sensor enhancer as they call it...... as time goes on the engine vacuum the PCM see's is low enough at idle to cause the PCM to stay in open loop from normal engine wear.... 16.1 inches of vacuum or less will cause this from what I discovered...... so the map enhancer is a cheap and easy way to get the O2 sensor to stay in closed loop.... I can make the PCM see 18.7 inches of vacuum at idle and it stays in closed loop all running conditions and rpm's...It makes the PCM see more engine vaccum which makes it lean..My recent emissions test went from 897 HC and 9.50 CO to 22 HC and .20 CO after I added the enhancer..... Map enhancer is last resort after you have checked all sensors and grounds....... 99% of the time a new O2 sensor will fix the open loop syndrome..... I have a DRB for the Renix and have worked at the dealer for many years in the Renix hey day on Monaco's, Premier's, Alliances and Jeeps........Silicone in the fuel will destroy the O2 sensor which I thought might be my problem, also I was pondering my exhaust temp was dropping below 850 degrees at the O2 sensor.... I tried 3 new o2 sensors I had stashed away and they all acted the same way.... fire it up, warm it up, all good for about 5 minutes, watch the o2 sensor go into closed loop on the DRB, coolant temp 210, IAT/ACT 165, sync working everything working like it should, even had a test light on the heater feed to o2 sensor and watched it..... increase RPM and let idle and o2 goes to .2 volts...sits their for a bit....then bang...open loop 4.97 volts........I pulled my hair out for days cleaning connections and stuff....All I know the MAP might be ioff calibration just a bit, Baro side reads right, just hate tossing 50 bucks for a map and it wasn't the problem.... Map enhancer cost me 14 bucks and saved me allot of money in TUMS
So with people without a DRB you can check to see if your o2 sensor is working with an Analog voltmeter that ranges 0 to 5 volts DC, tap one end into 5 volt reference to PCM at the O2 and the other to a good ground...... needle will move from almost zero to around 4.7 volts, back and fourth...you know its working..... use same method to set your map enhancer.... turn map enhancer clockwise in small steps and watch analog meter hooked to O2 sensor, when you can get the needle to move it's range at all rpm's and revving it up and letting idle then you have enhancer adjusted right...... I cannot tell you actual map voltage as I never hooked a volt meter to it while running and playing around with the enhancer...all set watching info on the DRB........
Okay, done blabbing
..... Just wanted to share my emissions adventure on my 1990 Jeep thats been giving me hell since I moved into town and had to do emissions last 2 years...........Also the map enhancer will increase gas mileage as you are making the PCM use a different set of fuel and ignition mapping based on MAP sensor reading
...just dont go to lean, you can actually turn the enhancer up to much and the engine will run hot and stall.......I only made the single mode enhancer, but i am going to make the dual mode enhancer so can flip switch from city to highway settings......
http://www.fuelsaver-mpg.com/simple-map-maf-enhancer
And again, thanks Cruiser for all the awesome info you took the time to share
:clap:
