car seems to lunge forward like your girlfriend lets the clutch out when she learned to drive a stick. The car misses or bucks sometimes real bad other times not at all. It only does it under 2500 rpm and at very little gas pedal presure. If I floor it it stops and it never has missed over 2500rpm weird
GM opti 10 months old
GM ignition mod. same
coil good
wires/plugs good
No bad codes are coming up either
car is a 93 Z-28 M6
What am I missing

 

You sure you got no arching on your plugs? Perhaps an injector isn't firing? Vacuum leak? MAF? IAT? IAC? All I can think of off the top of my head.

 

I put a new throttle position sensor what is the IAT and IAC again?

 

IAC is idle air control, its right below your TPS (throttle position sensor). The IAT is the intake air temperature sensor, its the one on the intake elbow by the maf.

 

My friend works at the A&A so we will try the iac iat tommorow.

 

That sounds a lot like what my 94 Z did when I had the rockers adjusted too tight. What kind of work have you done to your car and in what way did this problem start? Gradually, suddenly, or after some work you did to it?

 

my old z28 did that for 8 out of the 11 months i owned it.

problem was a leaking fuel injector. other symptoms were hard cold starts.

 

motor is untouched stock. It just started happening a few weeks ago out of know were. Whats the best way to look for a leaky/bad injector?
I'am selling the car so I need to get it fixed asap. Thanks for the tips so far

 

I think the way to check for a leaky injector would be to check the fuel pressure and see if it bleeds down or holds steady. You'll need a pressure gauge though. If you have the $10 Haynes manual it should tell you.