94 Cutlass Supreme Idle problems

[benniewillett]

Hi, This is my first post, and am very excited to be a part of your community. I have a 94 Cutlass Supreme Convertible 3.4L V6 Auto that I am having some issues that hopefully someone has encountered and has been able to correct. The car when started cold will not idle without keeping giving it gas. When cold before the rpms increase it hesitates, and slightly back fires before it accelerates. It feels as if it has no power until around 2500 rpms and then the acceleration smoothes out. When at normal driving speeds 35-45 when the acceleration is only keeping the car at a constant speed it feels as if it is missing. When coming to a stop the brakes do not have power assist unless the accelerator is depressed. When the car warms up it will idle, but it still feels as if there is no power and the idle is very rough.

I have replaced the Plugs (ngk copper), Plug wire set, Throttle position sensor. Idle air control motor, PCV ,Cleaned the IAC, Cleaned the MAF, replaced all vacuum lines that were questionable, there was one plastic line leaving the purge control solenoid that was broken, and vacuum line from Purge control solenoid was broken. I sprayed intake cleaner towards the front of the intake manifold gasket, and the rpms increased so i pulled intake off, and replaced gasket. after reinstalling and waiting for sealant round Coolant o-ring to set. I re sprayed around the intake, and found that the rpms would increase whenever the intake cleaner was on or around the fuel injectors. I inspected the Cat to make sure there was no blockage, and took out the honey comb material to ensure there was nothing restricting the exhaust.(I know that this will cause a loss of back pressure, however the symptoms are the same before and after cat was hollowed. After searching the forum I found some to have issues with FP Regulator, and I wanting to see if there may be another possible cause I may have over looked, as I hope that this will be the last time I have to remove the intake (installing new O-rings on injectors this weekend).
I hope my post was specific enough, and I again want to thank everyone for their contributions to the forum, I look forward to helping others as best as I am able to.

Thanks-Bennie

[maxwedge]

Should be scanned to look at fuel trims to see if it is too lean, and check the coolant temp sensor readings, when cold. Post back results.