94 Cutlass 3.4 Mising

I have a mis after 15 min of driving I have replaced 2 set of coil packs with modules, plugs,wires and a fuel pump. I took it to two shops they said it wasnt a mis it was a electrical problem. I now have replaced the pcm and its still doing the same thing. Before I replaced the pcm the check engine never came on. After I replaced the pcm it came on twice but went back off after I turned the car off and it hasnt came back on. I am stuck please help thanks:banghead:

Hey Bigb,
What kinds of codes did it throw out?
I could use some more info,
Was it Fine one day then bad the next or has it been gradual?
It runs fine while its cold and warming up?
(operating temp related) few temp sensors
For 15 min.s exactly?
( time related ) couple different things
Every time its cold or every time you restart it?
( reset / time table related) couple different things
Does it act up at or "miss" at all rpms?
( rmp vs tps lookup table related)

I don't understand this "two shops they said it wasnt a mis it was a electrical problem"
Does it have a mis-fire or not????? Did they give you a system Its all just FUEL+AIR+SPARK ratio vs TEMPERATURE vs THROTTLE vs RPM
Do only they mean that the problem is not from internal engine mechanical issues like broken valve springs, timing belt, no compression.
Electrical ?????:screwy:
Its all just- fuel, air, and spark. Fuel injectors, and fuel pump are electrical, Air intake temp, throttle position, and MAP are electrical, Spark plugs and timing are electrical.
Actual vacuume is the other but if you have compression you have vacuume.
The battery voltage and alt out- put and the system grounds are electrical.

It misses after driving for about 15 and it is after its wqarmed up.You can go somewhere and stay for an hour or so and get back in it it still does it but if you let it set over night it will start doing it all over again.To be honest I dont know what they meant that its electrail I gues like you said not internal in the engine.Will i have any codes with the light being off now? It was fine one day then doing this the next after I had a timing belt put on.when it starts missing it misses all through the rpm range.

Yes BIGBTRIPLETT you can hav codes even though thiers no sevice light.
Intermitant electrical can be challenging to track down and usually requires some wire tracing/testing. You could throw parts at it all day and never solve your issue(s).

If your miss was only after the timing belt was changed the crank position sensor wires could hav been nicked or damaged causing this. Might test that and see how it looks.

Hope that helps and Welcome to AF.

Yes BIGBTRIPLETT you can hav codes even though thiers no sevice light.
Intermitant electrical can be challenging to track down and usually requires some wire tracing/testing. You could throw parts at it all day and never solve your issue(s).

If your miss was only after the timing belt was changed the crank position sensor wires could hav been nicked or damaged causing this. Might test that and see how it looks.

Hope that helps and Welcome to AF.

Thanks I work at a gm delership so I will see what those codes were. I was just working on the car a the problem will seem to leave and work itself out and stay gone as long as you are driving. However you have to let miss for a while.