Hey guys. I have been out of circulation for a while. Before putting my GTA away for storage it was running like crap. I tried all kinds of things to fix or diagnose the issue, but to no avail. I just pulled it out of storage and I am back to troubleshooting. Here is the deal...

Very rich, super stinky exhaust (no black smoke that I can notice though). Under load, it surges, bucks, farts, stutters and misses. If I load it up just a bit (foot on gas/brake) I can feel a major miss and stumble, then it smoothes a bit, then misses again, and so on.

Here is where I am at:
- NO CODES
- scanned with computer - everything reports completely normal as far the computer is concerned

- new plugs (AC Delco)
- relatively new wires (Accel 8mm)
- new cap/rotor
- new distributor pickup coil
- swapped ignition coil
- had ignition module tested
- swapped EGR valve
- new EGR solenoid

I think that about covers it. I truly don't know what else to do, short of taking it to the shop. If anyone can shed some light on something I might have overlooked that would be awesome. Please, toss some suggestions out!

Thanks

Sounds like you may have one or more dead holes (unburned fuel in exhaust), one or more really bad injectors (leaking straight through), or no spark/ poorly timed spark on one or more cylinders (look for crossed secondary wiring). If you have done the "5-7 swap", those two cylinders will be effectively dead. Run the firing order again to be certain.