erratic idle in 3.1

I have a 96 GA with the 3.1 220k. I have been having a problem with erratic idle. I have checked all vacuum lines. replaced plugs, wires, fuel pressure regulator, maf, iac, tps, O2 sensor, and ran a can of seafoam through it. And still did not fix the problem. I am out of ideas and sick of putting money into my work car with 220k. Any suggestions would be greatly appreciated.

Still have not figured out this problem any help would be great

When you replaced the IAC & TPS did you pull the TB off and clean it out ??
Also was the IAC calibrated/set to 1 1/8" ?

I would go back over the entire engine and all vac lines again, but this time with starter fluid. I'm sure you'l find a leak somewhere. Do not be so quick to replace sensors, they are more trouble free then you would believe.

I dont know if I'd use starting fluid... carb cleaner is just as effective and a little less explosive for checking for vac. leaks.

Yes, the IAC was set to 11/8 and the TB was removed and cleaned. I have checked for vacuum leaks multiple times. Recently it has kind of come out of it some and only does it about once a week. So i guess ill just hope it eventually quits all together. Although today the water pump went out of it so maybe its time to say good-bye. Well if anyone comes up with another idea let me know, Thanks for the help ~Shawn

Ok did you reset the IAC after installing it ?

For this you just cycle the key "on" for 10 seconds, then off for 10 seconds, then start the engine and allow it to warm up.

Also did you check the vacum lines to the rear of the engine, and the one in the rear valve cover under the coils/ICM, could possibly be a small leak back there.
I've even seen misfires pop ones off a little in that rear area. :2cents: