Engine runs rough, and misfires and stalls

[ExodusFrank]

1995 Pontiac Grand Am 4 cyl Front Wheel Drive Automatic 138000 miles

Well, after replacing the O2, before I had a problem. Now I am beginning to think there is a new one. I unhooked the Battery (-) cable for a good half hour yesterday to reset anything but to no avail. When to start the car this morning to let it idle a little while before I was to leave, and the car didn't stay running for a minute before it sputtered to a stop. Started it back up...(It acted flooded at this point, took longer than usual to start, and I smelled gasoline as it finally started to run again, before apruptly stalling again. I drove it, and while driving on the road, the car dirves/runs/idles perfect. It's mainly on initial startup, and when you place the gear selector into gear, and begin to move in either R, or D that the thing sputters/hiccups, and trys to stall.

I can stay at a redlight, it will idle perfectly, and take off perfectly, it shifts fine and there isn't an SES light on either. It's been tuned up recently. (Within the past 6 months). I don't even know where to begin to diagnose it, but it's becoming quite aggravating to cope with as it really doesn't matter what the temperature of the car is it does it when hot or cold.

If it fails to stall, it will pick back up to around 1500-1800 rpm before finally settling back down to @ 8-900.

The problem never even existed until after the O2 replacment. Just with the new sensor now, its finally coming to light? All of my maintence is pretty up to date on the car, and did also go back with AC DP Plugs. Replaced the coil housing as well...(the white thing) My other was cracked boots were also replaced at that time because they were literally flaking apart.

Well, it seems as if the problem has now gotten a little worse than it was before. Since cleaning the IAC the car done perfectly fine for a few days, but now it still has a misfire on startup, and when trying to (save) it to keep it from stalling out on me, RPM's go completely wild, and will not fall. I have to shut the car down, and restart. The idle will reset then, but I'm still getting that lunge/hiccup until I can get the car going on the highway here.

The injectors are fine. I had a compression check and everything was fine. I put a different ICM on it and it wouldn't fire at all. The spark plugs are working normally, no sign of weak spark. The injectors are working fine, and it will occationally run smooth, other times it run ragged. It has 2 ignition coils. Misses through the drive range, from idle to around 2500 rpm.

[hinton08]

Do you have a check engine light on? If so, have you had the codes checked? If you smell gasoline, you need to diagnose that problem, as its a fire concern. If its coming from the engine, look for loose or broken fuel lines. If its coming from the tank, you may have a hole in your tank. Sounds like possibly your idle air control valve is sticking with your idle acting the way it is, but then again, its kind of hard to say without looking at the engine data on a scan tool.

[3100]

see what happens when you disconnect O2 sensor

if stalling stops, I would look into bad sensor connection or wrong O2 (mixed up wires)