Question about LT1 painless wiring harness.

[wood]

Hey all,

New to the board, had a friend send me here. I have a 87 z28 that I have put a 93 LT1 into. I am using the painless wiring harness, and I'm having some problems.

Here is what happens: I start it up just fine, idles fine and drives fine.. then after about 1-2 miles of driving it acts like it's been flooded and dies on me. I am able to restart it, and it wants to keep dying if I give it gas. After I let it sit for awhile it will run ok untill I drive it around again.

We pluged the code tester into the computer output and this is what it gave us:

-EGR - DUTY 0% (all the time)

-CODE 26 QUAD DRIVER MODULE FAULT

-EVAP DUTY 0% (all the time)

-"SOLENIOD OFF (all the time)

-MAP(v) 1.35 at idle, decreases to .9-1.0 at rpms

-MAP("HG) 105-11 at idle, drops to 105-8 at constant rpms

-OIL TEMP -34 degrees F

Everything else was working right, when we did the check we were just sitting there and it didn't crap out at all, we even drove it around a little (not far). So it seems like if you only drive it a few blocks it's ok, but when you drive and it gets warm it acts like the car needs more gas then it actually does and starts running way to rich and kills it.. Any help would be great.

-wood

[xxRillixx]

Hey,
There are a couple of us 93 f-bodies that are having the same problem. I'm still trying to locate the problem. Bigtow did you figure it out??

http://www.f-body.com/forum/showthre...nsmission+help

http://www.f-body.com/forum/showthre...?threadid=5508

I replaced my thermostat, and that helped a little... it doesnt get as hot as fast. Also, driving with the a/c on helps becasue it kicks on a fan. Im thinking about pulling them out and putting dual electric ones in to run constantly, as long as the car has power.

Im hopeing to take my car into the shop this week, ill let you know if i find anything out.

GOOD LUCK!!

[wood]

We did that test from the output of the CPU and it said the fluid temp was normal.. oil temp on the other hand...

What it seems like to me is when it goes from open to closed loop it is getting a faulty reading from some sensor somwhere that is causing it to fire rich. I was reading in another thread about someone saying they got on it and it was smoking pretty bad.. mine has done that to.

I'm pretty sure it has something to do with the wiring or a sensor somewhere. But I'm dead sure that it's a pain in the ass.

[TraceZ]

Try testing the temperature sensor located on the front of the water pump. It could be giving incorrect readings after it warms up a bit.

[xxRillixx]

Mine never smoked... or atleast i havent seen it. Maybe thats the next thing to come.

Posted by TraceZ:
Try testing the temperature sensor located on the front of the water pump. It could be giving incorrect readings after it warms up a bit.

Ill try that... hopefully its something that simple.

[wood]

Does anyone know where the EGR soleniod is located?

I think it means exuast gas regulator. Probley just an emissions thing? Would it cause the problem I am having? How about the incorect oil temp reading? Could that cause the computer to think the engine is colder that it actually is and fire rich?

Trying to juggle 2 chiltons and a painless manual and I am stuck here.

[xxRillixx]

how high is your temp getting? and does it make a jerking feeling before it dies?

I took my uncle for a ride, and he thinks its the differential or the 'throddle linkage'??... so im going down to his work so he can have his friend hook it up to some machine that moniters what the tranny and differential are doing. Hopefully i wont have to replace the tranny!! It could also be the 'throddle linkage' (no clue if thats what its called)... its like an upside-down U; right by the air intake. As you press on the throdle it movies from one side of the U to the other; it lets fuel in according to how open/closed the peddle is... that could be bad - thus sending too much fluid in with not enough air causing it to stall. This would also cause the incorrect oil readings. SORRY I FORGOT THE NAME OF IT! Anyone know what its called?

ill let you know if we find anything.

[TraceZ]

Originally posted by wood
Does anyone know where the EGR soleniod is located?

I think it means exuast gas regulator. Probley just an emissions thing? Would it cause the problem I am having? How about the incorect oil temp reading? Could that cause the computer to think the engine is colder that it actually is and fire rich?

Trying to juggle 2 chiltons and a painless manual and I am stuck here.

EGR = Exhaust Gas Recirculation
The valve itself is located at the very back of the intake manifold. The solonoid that activates it is located right next to it. Check out the picture....

[xxRillixx]

Ok... just got back from the shop. It is not the tranny or the differential. So im happy. The other things it could be are the control arm (i forgot the name last night) or the injecters.

[wood]

Anyone know where I can get a 93 LT1 wiring harness and cpu for a fair price? Gonna check the scrap yards tommorow.

still getting a code 26 from the scanner, but I did find out that I don't even have a mass airflow sensor.. also my main block temp sensor is not hooked up and I don't know where the connector is. I would just put on an aftermarket cold air intake but I'm thinking the painless harness+aftermarket parts+engine swap=confused cpu.

Hence I am on a mission to strip the www.painlessperformance.com harness out and replace it with the actuall 93 harness.. any advice?

[TraceZ]

Originally posted by wood
my main block temp sensor is not hooked up and I don't know where the connector is. any advice?

Get it pluged in! I'm fairly sure that is the problem. a LT1 will run like crap without a temperature sensor for the PCM.

I mentioned the temp sensor earlier in this thread as a possible cause

[fastTa]

Are you using the 12 circuit Painless harness?

[wood]

No, I am using the 93 LT1 harness they have under fuel injection It's supposed to allow you to put an lt1 into any car and still utillize some of the existing wiring.