95 CAVY, 2.2, STILL SKIPPINGl--HELP!!!!!!

here's the story: 95 cav, 136k miles, 5 spd, pulled the engine and trans, replaced head gasket and had head shaved .006, new water pump, clutch-pressure plate-slave cylinder, then back into the vehicle. Wires hooked up and the dash brakes/abs and air bag lights on--had a box hooked up to kill the circuits/lights and it runs. then to shop for inspection and did that plus replaced all injector seals as it was spewing fluid all over and had replaced #2 injector with a new one. got it from shop and still skipped minor but thought it was still some bad gas from 2 yrs sitting. got to gas station--filled it up and to home--"whats that smell?" gas tank leaking--back to shop and replaced tank, sending unit and pump and a few tired lines too--found out that #2 spark plug was cracked--they replaced them and new plug wires too. picked it up tonight--still skipping!!! about ready to throw the keys away and bury the damn thing. Can anyone give me some light as to where to start to look for the " skipping, hesitation, bucking and backfiring problem it still has? Should I take it to a chevy garage and have them put it on a diagnosis machine? the shop I have been tkakng it to is a reputable shop that deals a lot in foreign cars and I trust their judgement....thank you in advance for the help!!!

Sounds like an ignition problem. Make sure none of the plugs got cracked upon installation,and are torqued down well. Wet the wiring(preferably at night,in the dark) and snap the throttle to make maximum kV demand on ignition. Use a test light grounded at batt and run it along the plug wires while snapping gas. Any spark leakage will cause a miss. Make sure the injectors aren't leaking externally...common problem. I hope you are using AC platinum, or at least NGK's and not the Bosch plugs, they are trouble.

http://www.automotiveforums.com/vbulletin/showthread.php?t=484476 Yeah, stay away from the Bosches.

I had an old school mechanic look at the car--the EGR valve was not working properly. He plugged the vacumn hose and it ran fine but the gas mileage sucked. Pulled off the valve, pushed up on it and it pushed/pulled air correctly, used carb cleaner and cleaned it and re-installed it. It seems to run fine today but will keep you posted as to its performance. Thank you again for the reply/help..