Help pls...95 gp 3100 rough running

[95gpadam]

Hi
I have a 95 grand prix with a 3100 engine, for the past week it has been running very rough. Originally I thought it was the o2 sensor since it would run fine when cold and then like crap when warmed up. I unplugged the o2 sensor and it ran like a champ until i got it replaced yesterday. Now it runs horribly with the o2 sensor both plugged in and not plugged in. It smells extremely rich and bogs on acceleration (almost got nailed a couple times yesterday) I have heard that injectors may be the cause, but I don't know how to be sure of this. Has anyone had a problem similar to this, I did search the archives, but it seems like there are a lot of suggestions but no final verdicts. My SES light used to come on intermittantly before the problem at around 100km/h but is not on now (and isn't burned out, I checked before starting)

So far, I have
-replaced air filter
-replaced fuel filter
-replaced o2 sensor
-cleaned IAC sensor
-ran engine with EGR valve connector unplugged (not sure if this proves anything, but its free so i tried it anyway)

How can i go about checking if one of my injectors is stuck open?

Gonna go check my coil packs and wires now....any and all suggestions are welcome and appreciated. (Need to get this thing running right, have to go back to school tomorrow ~400 km trip)

Thanks
Adam

[bszopi]

RE: Help pls...95 gp 3100 rough running

Might check the fuel regulator as well. That has been a common problem recently.

First check, pull the vacuum line off of it and see if fuel comes out. If so, then its definately bad.

Next, check the pressure at the test connection. It should be around 45psi at idle.

[95gpadam]

Just went and check the wires and coil packs, they seem to be working fine. Sat in the car when I started it, it is more of a very lopey idle, the car will idle at 900 for about 4 seconds and then shoot up to 1500 for a sec and then back to 900.

Thanks for the suggestion bszopi -- The Fpr is the one that is beneath the air box, with the vacuum line attached to the plenum, right? Or is it the small thing on the end of the fuel rail?

[bszopi]

Small thing at the end of the fuel rail.