Ok, let me start from the begining. I just have my motor overhauled (complete long block-included valve job, resurface heads, new vavle springs, vavles, new pistons, reconditioned crankshaft, new bearing, regrind cam, new timing set, and all new gaskets) and along with that i have new waterpump, spark plugs, starter and battery. I have had now for about 5 days

Now when i was driving home last night (the 2nd) it was idling and driving rough and seemed like it wanted to die and less i gave it some gas (this was with me going at the most 40). So today when i started it, it was idling rough again and would have probably died if i didnt turn it off. does this sound like anything to you? what would you recommened? should i get a diagnostic test? any help would be great.

p.s. this is for my 95 Z28, all parts replaced were stock and the old optispark is about 2 years old

thanks
Michaelangelo

 

when my opti went bad in my 93 A4 Z, the car would never try to die...but would always rev itself and buck when driving. Although, in my M6 93 Z, the car would just lose rpms when at idle and then sometimes die as you'd be going down the road. Now, your problem could be your opti and it also sounds identical to a bad fuel pump. Can you hear your fuel pump making a whistle type sound from inside or outside the car? if not, then you might be ready for the opti change.

 

Is it throwing a light? If not then almost has to be either the Fuel pump or filter , or the ign system, make sure that you have all the ECM Grounds in place as well.

 

my opti and fuel pump both threw a SES light. So it'd be hard to tell from just the light. If it does throw a light, have it scanned. It'll save ya lots in the long run.

 

well no light came on, someone else said maybe coil or coil wire? what do you guys think? how hard is it to replace?

 

Sounds like the EGR is stuck. Causes a bad idle unless you trottle it up and when trying to idle it will die. Take a look at it. Check the IAC while your there too.

 

How did the fuel pump throw a light? There is no monitor for it. I had a fuel pump go stone dead on me and the computer was never the wiser. The EGR could be it as well if it is stuck open it will idle rough and run crappy at lower speeds and die in gear with your foot on the brake. One way to test the EGR without any fancy tools is if you can get it to idle reach under there and push on the EGRs diaphram and it it runs even crappier its not it but if there is no change then its probably the culprit.