Chevybassguy

Hello all. I have been going crazy trying to figure out this issue with my 95. Here's what happened. Last Saturday morning the car was driving fine. Then it started surging a little bit at idle. Nothing much maybe 200 RPMs. Then my wife was driving it that night and the car backfired and died. I got it home and started diagnosing what it could be. Here is what has been replaced and checked recently. The car has less than 800 miles since being rebuilt with an all new opti, plugs, wires, MAF, IAT. I have checked all of the vaccum lines and just last night I pulled out the IAC and cleaned it because it was pretty dirty. I also pulled out the EGR valve to check the diaphragm and everything is functioning and looks good. I am not a mechanic but am pretty good with this kind of thing usually. I am going to pick up a fuel pressure tester tonight and check that.
The car will start but now the idle surges pretty bad almost 500 RPMs. And then if left idling will just die after 30 seconds. If I give it throttle it will run and sounds fine. But it will not idle. Could this be the fuel pressure regulator going bad? I am just posting this because I have read just about every thread involving something like this and am at my wits end. I am wondering because it is getting progressively worse what it could be. Maybe I just don't know enough and I'm missing something simple. Any help would be much appreciated. Sorry for the novel.

Chevybassguy

I just checked and the fuel pressure is good at 42. And it is not bleeding off after the pump shuts off, which I believe is what it is supposed to do. Also I am still pretty sure it is somewhere in the EGR system. I pulled the fuse for the AIR pump and the car actually idled without stalling. But it idled higher than it should. Does anyone have any ideas for other things to try?