Ok, heres my situation: I bought my car 2 years ago. Its a 91 z28 w/ l98 and almost every option (excl leather). Its a fairly low mileage car at 46k. I have begun adding some go fast goodies. I added flowmaster cat back, removed air baffles and got k&n's, new taylor 8mm wires, all new gaskets, cap, rotor, spark plugs. I also added a new sound system .My car's "SERVICE ENGINE SOON" light would keep coming on. but driveability was never affected. No code could be pulled. The engine light began coming on more and more frequently. Then. when the light came on, the car would idle extremely roughly, and would idle itself out. I took my car to a mechanic (friend too) to see what he could do. He ended up replacing the ECM. Car ran beautifully w/ new computer but then after about a month my car had the same symptoms. I got another ECM and plugged it in and seemed to have solved the problem again. After storing my car for the winter i recently took it back out. Car ran great for a week and then same problem again, this time on a few occasions the car would not start. With a rap of a hammer on the starter it would then start up. So i replaced the starter and seemed to start engine fine. Then I go to fill up at the gas station and the car would not start. Got it towed back to my house and now need help figuring out what is wrong and what to do to get it running better than new. Also, when the engine light was on and it didnt idle rough the car was very sluggish, as if there was a delay before acceleration. Any input wil be greatly appreciated.

 

Replace fuel filter, I assume you got a new cat or are not running one?

 

Still have factory dual cats. Also have new fuel filter. When the key is turned the starter doesn't even click.

 

Do any accessories work. If not check the ground to your battery.

when you get it started check to see if the cats glow when the car is warm.

 

Some accessories work, some dont. I know the power hatch release doesnt work, but radio can turn on, windows can go down.
I'm pretty sure the cats are fine. When i do get it started i will look to see if they glow though. I want to get rid of them all together but then i can't pass e-check.I may just get rid of them and make my own "cats" by just welding the outer shell to regular pipe. But thats in the future, and so for now.......

 

Check your fuseable links down near the starter, they can cause exactly the problems (with starting) you described.

~M~

 

This may sound like a dumb question, but what do you mean when you said you "removed the air baffles?" Are you referring to the MAF sensor? If you messed with that and screwed up the sensor, it could be grounded out or have a short in it, which could possibly fry the ECM, which would explain why it worked for a while when you changed computers, but then acted up again.

 

Blazin,

If you cannot retrieve codes from the ECM, you have a problem. Presuming that the ECM is functioning, since the engine is at least running, you may have an ECM wiring harness problem. At the very least, you should be able to retrieve a code '12'. A close inspection of the ALDL socket and wiring is in order. Make sure the contacts are in place and the wires are connected from the back of the connector. Grounding the 'B' terminal with the key on, engine off, should set the ECM in the diagnostic mode - always.

Since you are on your third ECM, I doubt the problem is in the little silver box, but is more likely in the spaghetti.