95 Bird Idle Problem

Out of no where one day, my car (95 4.6 V8 LX) stalled. When re-started, it would stall again if I didn't hit the gas. It wouldn't idle, so after (what I thought was) process of elimination, I figured it was the IAC valve, so I replaced it and it seemed to fix the problem... for a few days. Long story short, I took it to a mechanic and they replaced the MAF sensor (cuz the sensors were bad, leading to the stalling) and my car hasn’t stalled in park since.

I say in park because of a new problem. My car now idles very rough in park, neutral, and when stopped in drive since they replaced the MAF sensor. There are very sporadic surges and drops that go as high as 1.5k RPMs and as low as .4-.3k RPMs. In fact, to test it out, I put it in neutral one day after driving it for a few minutes and it stalled out. So, I took it back to the mechanic and explained the problem. He plugged the car into the computer and replaced a supposed bad O2 sensor. The car ran fine for 2 days after, and now the "roughness" is back. So rough it shakes the entire car when it's in park, and when stopped in drive.

I only post this thread because I am dumbfounded at this point. I listed all these problems just incase there’s no coincidence between them. I am hoping someone, somewhere out there has had any sort of similar experience with my problem or knows what’s going on, because I don't, and clearly my mechanic doesn't either. ANY advice would be helpful at this point.

Thank you, Paul

Out of no where one day, my car (95 4.6 V8 LX) stalled. When re-started, it would stall again if I didn't hit the gas. It wouldn't idle, so after (what I thought was) process of elimination, I figured it was the IAC valve, so I replaced it and it seemed to fix the problem... for a few days. Long story short, I took it to a mechanic and they replaced the MAF sensor (cuz the sensors were bad, leading to the stalling) and my car hasn’t stalled in park since.

I say in park because of a new problem. My car now idles very rough in park, neutral, and when stopped in drive since they replaced the MAF sensor. There are very sporadic surges and drops that go as high as 1.5k RPMs and as low as .4-.3k RPMs. In fact, to test it out, I put it in neutral one day after driving it for a few minutes and it stalled out. So, I took it back to the mechanic and explained the problem. He plugged the car into the computer and replaced a supposed bad O2 sensor. The car ran fine for 2 days after, and now the "roughness" is back. So rough it shakes the entire car when it's in park, and when stopped in drive.

I only post this thread because I am dumbfounded at this point. I listed all these problems just incase there’s no coincidence between them. I am hoping someone, somewhere out there has had any sort of similar experience with my problem or knows what’s going on, because I don't, and clearly my mechanic doesn't either. ANY advice would be helpful at this point.

Thank you, Paulmost local autoparts stores should be able to check the codes for you. get the codes and then post them up here. that should give us all a better idea of what is wrong.

did you try the tps (throttle position sensor)?

94-95 Tbirds in particular had a problem with the vacuum lines going to the egr valve splitting. This is located at the rear of the engine. Take all of the vacuum lines including elbows and connectors that are in the vacuum circuit going to the egr off and check them carefully for cracks or splits. A friend of mine had a problem with rough idle and a fault code of one side lean with a split connector being the problem.