I don't own an F-body, I own a Lumina Z34, however, this pertains to electronics and emissions, and it's all the same for GM cars(relatively).

I keep getting a code 32 & code 43(which I believe is the Electronic Spark Control). I understand what the codes mean, however, I don't understand what could have caused them. The EGR is an electronic model, not the vacuum operated version. I replaced the EGR, thinking that it *might* fix it. It didn't hurt, since I got it for free at the parts store my friend works at. It didn't fix the problem, even though I cleared the codes.

Any ideas for fixing it? The symptoms are as follows; lumpy idle, it's in fast idle for at least 2 or 3 minutes, when the gas is tapped at fast idle, RPMs drop by approx. 300 before raising, acceleration is horrible, it's hard to start, and there is a miss in the firing.

If I can get this fixed, I might keep the car. If I can't, I'm just going to accidentally wreck the thing and get the insurance money from it to buy a muscle car.

 

Do not worry about the EGR right now it should not be that big of a deal. As for the ESC we will attempt to track that down. It sounds as if the ignition is retarding to much. (You should have little or no knock retard at idle) Do you have access to scan tool? This will help in determining if the ECM is retarding the timing too much because of a faulty ESC module. If you do not have a scan tool and the engine has a distributor you may be able to determine if the timing is being retarded by using a timing light. Also check the connections at the module very carefully and at the knock sensor.

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[This message has been edited by 84IROC (edited November 26, 2000).]

 

Tanner,

Welcome aboard!

I'm not the famous GM Tech you're seeking, nut I might be able to help a bit.

The digital EGR valves are usually pretty reliable - much more so than the vacuum controlled type. Unless the ports are plugged with carbon or the valve is mechanically damaged, they should last "forever". What teh ECM might be trying to tell you is that it doesn't sense the EGR valve opening, even though it has commanded a move by the valve stepper. The EGR will verify this by one of two means. Either it will expect to see an increase in manifold pressure (decrease in vacuum) or it will have a temperature sensor in the EGR system to verify flow.

If your EGR is stuck open, you can also get the DTC. This might account for the high/poor idle, lean reaction at throttle tip-in, and hard starting. Even if the EGR is O.K., a different vacuum leak might cause the same symptoms. Check all the hoses, PCV system, and don't overlook the brake booster. I has a booster that was starting to fail and it drove me freakin' nuts trying to figure it out. The unit still gave good braking assist, but was leaking enough internally to cause pretty bad operating conditions.

What year/engine is the Lumina? I'm guessing it's a 3.4L...

 

It's a '92 with 118,000 and change. Yeah, it has the 3.4LDOHC. Stock it pushes 210@5200 and 215 lbs./ft. @ 4800RPM. The motor is a mechanical miracle, however, it's a nightmare for mechanics due to the limited working space(I had to pull the coolant overflow tank just to gain access to the serpentine belt).

So more than likely it's a loose/leaking vacuum hose?

 

Has a timing belt ever been put on this car? There is a very compicated procedure that must be followed word by word, with special tools in order to do this. It is very easy to screw up, and if even one of the four sprockets is off a tooth, you can experience such drivability problems. With 118,000 miles, I'm sure it has had at least one put on.

But before I scare you about the timing belt, the most common problem with the digital EGR valves is like Vader mentioned, carbon buildup. Pull the EGR valve off and poke through the hole with something stiff like a coat hanger and see if it gets hung up, you can bust through the carbon with the hanger.
As for the other code, the most common problems I see is the knock sensor, or the wire going to the knock sensor. Usually within the first 8" of wire coming from the sensor, the actual wire breaks inside the insulation. I would try a new knock sensor first.

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I'm not sure on the timing belt. I got it with 98,000 on it. I'm sure it has been though, since the guy that owned it was a GM Mechanic for Pedigo Chevrolet.

Thanks for the help, all of you.

 

I had the same problem with my 90 Lumina 3.1 I found out it was the ignition module under the 3 coil packs. It seem only 4 cylinders were firering instead of the 6

 

Well my wife had a 1992 Lumina Z34 and it was a great car. It had the same problems and eng. that your car has and i chased the problem all around. I went to the NHTSA web site and looked at all the TSB from 92 to 96 and found a winner. The intake manifold gaskets were leaking and the eng. had a high idle when the eng. was cold. When it warmed up some the idle came down. I did waste $ on an IAC valve though. I am not sure if this is your problem but i would bet money on it.

-Auggie-

 

Here's an interesting one for you to ponder. We had a Grand Am in our shop once that was acting up horribly. We couldn't even get any codes using a scanner. We replace the ignition module and the coil packs, and tried replacing just about everything you can imagine. My boss lost sleep over this one for like a whole week. Finally, he looked at the mass air flow sensor and found like a little friggin piece of lint or something stuck in the filament, and that was the whole problem! Just something else you might want to check. Sure can't hurt!



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