renix running very rich

[BPB]

Ok got more gas in it. One thing I forgot to add is that at this point the only exaust on it is the down pipe. But it has ran fine with out it.

So here is the full data report.
O2 4.98v
Throttle 13%
Inj (ms)6.8-9
Rpm 575-685
Map 2.1v
Map 50 kpa
Man vac 51 kpa
Baro pres 102 kpa
Measured vacume is 14 in/hg but it drops to 12 and jumps up to 16 occasionally
Measured fp is 31 psi idle and 39 when I unhook the vacume line.
Coolant is 75 degrees c
And prom b1943ffc whatever that means

I can tell you that the exaust is no lean because it smells like a stock 350 with an 1000 cfm carb on it

 

[cruiser54]

O2 staying at 4.98 volts? Not cycling from there to .1 or so?

 

[BPB]

Nope just stayed steady. So I made an egr block off plate, and after a couple beers I decidedv to truss it. I also noticed that there is no egr tube, its plugged. Then it doned on me that 5 years ago when I put the header on it there was no egr fitting. So after installin the egr block off plate it ran great for about 10 minutes then whent to crap. I pluged the vacume line that goes to the round sphere and re started it and it was better. Today aftr work I'm gonna grab a handfull of vacume caps and do some more trouble shooting
Here's my block off plate.

 

[Ecomike]

1990 mj 4.0 ax15. The exhaust smells like fuel, i burned through $10 of gas in the driveway firing it up trouble shooting.
I have a parts motor that ran perfectly about two weeks ago. I swapped the fuel rail (with injectors), throttle body (with sensors), distributor, every sensor on the motor minus the o2 sensor and ckps. All to no avail.
Next I pulled the ecu wiring harness, thoroughly inspected it, cleaned every contact and used dielectric grease on all connectors I even soldered a couple factory crimped connectors. At the same time I swapped egr valves and installed a new gasket.
It ran great for almost a minute then it went to crap.

Then I bypassed the inline fuel filter with fuel line and bypassed the ballast resistor. this didn't help and the fuel filter wasn't restricted. Any Ideas?

WOW!

You might try swapping the bumper bearings next, but it might have been easier to just swap the entire Jeep?

LOL.

Just read the entire thread, and I suspect one of your problems is no 12 volt signal to the O2 sensor's electric heater, or a bad O2 sensor, or both. The 12 volt's to the O2 sensor heater goes through a relay.

Follow this next, or waist more time and money, IMHO:

http://www.naxja.org/forum/showthread.php?t=1012701&highlight=oxygen+sensor+test

 

[Crashsector]

If the O2 sensor is reading near 5V it's bad. Rich should be making it read close to 0V. Part of your problem. Is the brick reading RICH or LEAN?

What is it saying for Intake Charge Temp?

--Andy

 

[BPB]

lean
and off the top of my head it was 14? if that sounds right, I am going to use it again some time this week

 

[Crashsector]

If it's running rich, and the computer thinks it's lean, I think you have pegged your problem. Something with the O2 sensor or harness to the O2 sensor.

14C doesn't sound right for the intake charge temp either. With the engine cold it should read what ever the outside temperature is. Normal running temps are around 60-80C.

--Andy

 

[Ecomike]

If the O2 sensor is reading near 5V it's bad. Rich should be making it read close to 0V. Part of your problem. Is the brick reading RICH or LEAN?

What is it saying for Intake Charge Temp?

--Andy

Not correct. The O2 sensor could be good. Also, I think you have the rich/lean voltages backwards:

http://www.naxja.org/forum/showpost.php?p=244782813&postcount=27

Info relative to Renix O2 sensors:

http://www.dnd-automotive.com/tuneup/02-sensor.htm
Some vehicles are equipped with a different type of O2 sensor that has a titania rather than zirconia element. Instead of generating its own voltage signal, a titania O2 sensor changes resistance as the air/fuel ratio goes from rich to lean. Instead of a gradual change, it switches from low resistance (less than 1,000 ohms) when the mixture is rich, to high resistance (over 20,000 ohms) when the mixture is lean.
The engine computer supplies a base reference voltage of approximately one volt to the titania O2 sensor, and then reads the voltage flowing through the sensor to monitor the air/fuel ratio.
When the fuel mixture is rich, resistance in a titania sensor will be low so the voltage signal will be high (close to 1.0 volt). When the fuel mixture is lean, resistance increases and the voltage signal drops down to about 0.1 volt.

I would be curious to see what the actual voltage output of the O2 sensor is at the O2 sensor during acceleration and deceleration (not data at the brick that is asking the ECU what it thinks the number is), does it drop at all from 4.98 V at the sensor? Is the ground wire at the O2 sensor open circuit?????

Is it getting 12-14 volts to the large orange wire, to the O2 sensor's internal electric heater??????

 

[cruiser54]

Watching on a scanner you should see the O2 switching every coupla seconds if not more often.

 

[Ecomike]

Watching on a scanner you should see the O2 switching every coupla seconds if not more often.

He said it is reading 4.98 V on the brick scanner. I told him to check with a meter at the sensor itself, and to gun the engine, accell-decell, to see if it moves at all (any response), and to check the ground and the heater voltage wire to the O2 sensor.

No reply back yet.

 

[cruiser54]

Yeah, I know. Just reiterating the importance of checking the O2 sensor.

 

[BPB]

Alright I picked up an analog meter for testing the o2 sensor and a pack of vacume caps. Ill be workin on it tomorrow after work. I might throw the caps on it tonight when I get home

 

[BPB]

I plugged all of my vacume ports exept the fpr and map and ired it up, it ran horrible right away, next I tested my o2 sensor I have 13.9 volts to the orange wire and a steady 4.8 volts to the sensor according o the power probe, digital multo meter and analog multi meter

 

[Ecomike]

O2 sensor ground test data?

O2 sensor output voltage during deceleration and acceleration read by analog meter at the O2 sensor? Does it ever sweep down to 1-2 V range or stays at 4.98 V?

 

[BPB]

Stays at 4.8 ill have to get more ass for it to test the excel decel

 

[BPB]

SOLVED!!!!! Ecu was bad

 

[cruiser54]

Glad you found it. I wonder where the scanner gets it's O2 sensor data, from the sensor itself or the ECU?

Where did you score an ECU?

 

[Ecomike]

What exactly was wrong with the ECU. 5-90 wants bad Renix ECUs, so don't toss the bad one!!

 

[BPB]

I borrowed one from another member that I'm trying to buy. The part inside the metal is bad. I swapped it and now its fixed

 

[cruiser54]

Like Mike says, 5-90 wants bad ECUs. He contributes alot to the community. It would be really cool if you shipped it to him.