I'm still having idle problems in the GF's 1990 Chevy Beretta 2.2 . It has a horrible bog if you snap the throttle to the point of stalling, but if it's in neutral there is no problems at all with it. In gear at idle it's very harsh and vibrates excessively.

It has a new MAP sensor, new head and gaskets for intake manifold etc.

The EGR was unplugged due to a pinhole leak in it and the TCC Solenoid was unhooked due to it malfunctioning and preventing the trans from downshifting.

I've done the basics like new plugs/wires cleaned the throttle body, new fuel pressure regulator.

This problem was just as evident before we had to put a new head on there. So Im guessing it has to do with something else. I've sprayed with carb cleaner to check for vacuum leaks and checked the vacuum with a gauge and it all looks fine at idle/acceleration.

I'm going to check the coil packs soon, but it doesn't seem like it would be those since the problem is not evident at idle.

Maybe the EPROM is bad? Any more suggestions would be greatly appreciated

 

Could be the timing or the O2 sensor or both.

 

Thought I put in a replaced the Oxygen sensor, now that I re-read the thread I didn't. So yeah it's been replaced already and the timing is dead on.

 

When you say you unplugged the EGR, did you remove it or just remove the wires? Also, if you removed it while it was open, it might stay that way.

Crappy idle is usually due to bad air/fuel ratio, incorrect timing, or air leaks. You seem to have covered all of the basis on these so the EGR seems to be the only thing left. Maybe your ECU is malfunctioning...?

 

There's no wires to the EGR it's the old school style with just a vacuum line, I unhooked the vacuum line and plugged it off. That was our next step was possibly a new PROM which is like $80 from the dealer. It flashed a Check Engine Light on for a few minutes today then turned off, so I'm going to see if there's any stored codes ASAP.

 

I'm not sure exactly how the vacuum operated EGRs work, but I would say its a possibility that its stuck open.