95WHTLT1

This is 95 z28, O.K. first of all, car is real hard to start when cold(fuel pres. reg?) When it finally starts it is really hard to keep it idleing. Too much gas, it goes dead, not enough, it goes dead. Then when it does idle by itself and you punch the gas it stumbles real bad then revs up, sometimes it will pop. There is also an airy sound as if there is a vac. leak when you do this. It will rev all the way to redline with no miss if you slowly rev it up. And I can't hear the airy vac leak sound. It is calling up SES and the fans come on immediately after it starts. I took it to the local precision tune and they said it was a bad pcm. Now for the new parts put on this car...plugs, wires, opti, iat, tps, intake gasket, egr, intake elbow(alum w/ k&n filter), temp sensor in water pump, fuel filter, coil, coil module, and the pcm. The only things I can think of are tha MAF and fuel pres reg. Anymore suggestions???? All these problems were present before I put on the new parts. And there has been no change.

shoebox

Get the diagnostic codes from the scan and post them. You have had your hands on so many things, it is now near impossible to try to pinpoint.

Injuneer

The reason your local "Precision Tune" said you have a "bad PCM" is because they saw the 16-pin OBD-II ALDL connector on your 95, and tried to scan it with an OBD-II scanner. Won't work, since your 95 has an OBD-I PCM.

Seems like is would have cost a he!! of a lot less to get it scanned correctly and find out the source of the problem, rather than investing in all those parts without knowing why the SES light was on.

Guest47904

See very little if any diagnosis and just throwing parts at it. The very least reason you don't throw parts at the problem is because as in the case of the wiring problems, parts don't fix it.

No history of the vehicles running condition doesn't help us either.

95WHTLT1

Wasn't really throwing parts at a problem. Car had developed the dead spot that I mentioned, very soon after that the opti went out. Installed new opti, wires, plugs, coil, coil module at the same time. Intake elbow had a cut in it so it was changed also along with the iat sensor that is mounted in it. While doing this I changed the intake gasket which was leaking a bit and while this was off I changed the egr. So it might sound as if I was throwing parts at a problem..sorry if it came across that way. Now since it so cold outside it won't run well enough to drive it to the chevy dealer to have it scanned. Not to mention I go into work before they open and don't get home until well after they close 5-6 days a week. I have another car so I'm not that desperate to get this running, just looking for suggestions. Car has about 150K on it, no mods, all stock.