Cruiser's RENIX diagnostics thread

My MAT sensor was bad when I had that problem. Manifold Air Temp sensor. 1 ohm is OK on the ground. Some meters read .5 to 1 ohm on a dead probe to probe short.

4.65 V input is a sign of losses in the wires from the ECU power supply inside the ECU!

.02 V is also OK on the diffy.
 
The MT2500 would be great for observing the O2 sensor.

Looks to me like you checked the wrong side of the sensor. Those values are for the auto trans side. Use the flat 3 wire connector with .17 as a multiplier. You see, one side of the sensor can be bad while the other side is good. In your case, the "engine" side may be bad.
 
cruiser54 said:
The MT2500 would be great for observing the O2 sensor.

Looks to me like you checked the wrong side of the sensor. Those values are for the auto trans side. Use the flat 3 wire connector with .17 as a multiplier. You see, one side of the sensor can be bad while the other side is good. In your case, the "engine" side may be bad.
Click to expand...

Huh - maybe I didn't understand the directions. I'll look at them again...

YEP!! I tested the wrong side connecter. But where is the "D" connector on the flat 3 wire plug?
 
I don't have the scanner hooked up at the moment, but the last time I did (3 days ago) I noted it said something about a lean condition. Something I should be watching?
 
I can only speak for the DRB but you should see the O2 sensor going Rich-Lean, Rich-Lean rapidly. Of course, the O2 is not causing your high idle anyway. Just good to know.

Has this high idle always been an issue or did it just crop up?

You did the sensor ground test and wiggled the wires?
 
cruiser54 said:
I can only speak for the DRB but you should see the O2 sensor going Rich-Lean, Rich-Lean rapidly. Of course, the O2 is not causing your high idle anyway. Just good to know.

Has this high idle always been an issue or did it just crop up?

You did the sensor ground test and wiggled the wires?
Click to expand...

Idle just came up after a 1000 mile trip. It just started the other morning.
What is the sensor ground test? Is that measuring the resistance? If so, yes - 1.002 ohm.

Right now I am waiting for my co-worker to return from lunch because I think he left with my volt meter.
 
JoshInReno said:
Idle just came up after a 1000 mile trip. It just started the other morning.
What is the sensor ground test? Is that measuring the resistance? If so, yes - 1.002 ohm.

Right now I am waiting for my co-worker to return from lunch because I think he left with my volt meter.
Click to expand...

Sensor ground test is in the TPS instructions. That's the one you did with the key off and wiggling the harnesses?
 
cruiser54 said:
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.
Click to expand...

This is the only other test I see?
 
That's the one. So you got a little more than 1 ohm of resistance. What happens to that value if you wiggle the harness that parallels the valve cover and over near the MAP sensor.

That's on older version of my instructions. Did you get that off my thread or the link in my last post on that thread? Here's the new one.


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: With the Key OFF, and 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. Wiggle the wiring harness where it parallels the valve cover and also over near the MAP sensor on the firewall. If you see more than 1 ohm of resistance, or fluctuation in your ohms reading, 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 only a flat three-wire TPS mounted on the throttle body and it provides data input to the ECU. It 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. Loosen both T-20 Torx screws attaching the TPS to the throttle body and rotate the TPS until you
have achieved your desired output voltage. Tighten the screws carefully while watching to see that your output voltage remains where it is supposed to be. If you can't achieve the correct output voltage, replace the TPS and start over.
Sometimes, after adjusting your TPS the way outlined above, you may experience a high idle upon starting. If that happens, shut the engine off and reconnect your probes to B and C. Start the engine and while watching your meter, turn the TPS clockwise until the idle drops to normal and then rotate it back counterclockwise to your desired output voltage.
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, as outlined above—FOR ALL 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. THIS SQUARE FOUR WIRE CONNECTOR IS USED FOR TRANSMISSION/SHIFTING RELATED ISSUES ONLY. 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.
FOR AUTOMATIC TRANSMISSION RELATED ISSUES: Check the square four-wire connector side of the TPS.
If you have ENGINE ISSUES check the flat 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 09-22-2012
 
cruiser54 said:
Cruiser’s Renix Sensor Ground Test
Set your meter to measure Ohms. Be sure the key is in the OFF position. 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. Wiggle the wiring harness where it runs parallel to the valve cover and also near the MAP sensor mounted on the firewall. If you have an 87 or 88 with the C101 connector mounted on the firewall above the brake booster, wiggle it, too.
You want to see as close to 0 ohms of resistance as possible. And when wiggling the harnesses/connectors the resistance value should stay low. If there is a variance in the values when wiggling the wires, you have a poor crimp/connection in the wiring harness or a poor ground at the engine dipstick tube stud. On 87 and 88 models, you could have a poor connection at the C101 connector as well.
Revised 05/03/2012
Click to expand...

I see this now.
 
Be sure and test the ground on both sides of the TPS!!!!! One or both grounds can be bad!!!
 
Resistance at B with key off: 0.7
Wiggle test: 0.8

Key on -

Reference: 4.9v (A to B)
Output: 0.64v (B to C)

So if I understand the directions correctly (I sure hope so), my output needs to be adjusted to 0.83v? 4.90 x .17 = 0.833
 
Last edited:
I use .82 so that is close enough. Test the MAT sensor, disconnected and see what the resistance is at room temp and hot and post the data and apx temps.
 
Ecomike said:
I use .82 so that is close enough. Test the MAT sensor, disconnected and see what the resistance is at room temp and hot and post the data and apx temps.
Click to expand...

This thing?

getimage.php
 
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