I'm having a problem. Mine is at startup and while the engine is cold. My engine revs over 2k at startup and falls down to around 1500rpms and slowly drops til it reachs 800-900. When I attempt to drive, it will bog down or quit. You never know when it's going to happen. It just does. With or without a/c on. Once the engine gets hot this doesn't happen anymore. It's annoying while cold.
PW techs think it's a vac leak. I checked everything several times. Used propane to look for leaks. I replaced the IAC, no help. I'm installing a new TPS tomorrow. To see if this does anything.
I find that the propane method really does not help me. Use something that will mist. Then u can spray it near all the lines (go slow so you dont miss it) and when u see the mist going closer/moving abnormally then u prolly found it.
I had the propane torch set high and went slow. Following every line in reach egr,manifold,maf etc. I did this twice.
I wanted to see how effective the propane was in finding a leak. So I did a test. I added a vac. line to the intake manifold and made a small hole and shot propane on it. It did nothing. I had to enlarge the hole to a descent size before the propane would have an affect on the idle. Something this size I would be able to hear it. So I found out propane isn't that effective in the manner unless it's a large leak.
Isn't brake cleaner harsh on rubber hoses and such? I didn't want to spray everything down with something like that. If the new TPS doesn't fix my problem I may have to. I don't think I have a vac leak. There's only so many spots to check and I've done them all, over and over and over.
I finishing installing a new tps today. I ended up removing the TB to make it easier. Well I started it cold and it still rev's high. But the idle seemed to drop down to normal level quicker and it didn't bog or stall on me. It'll have to continue running like this for a few days for me to call the problem fixed. The TPS was cheap Under $30 at AutoZone.
Just discovered another thing to check - double-check your throttle and cruise cable routing.
Make sure they aren't stressed or binding where they attach to the cable bracket. A stressed cable anchoring could randomly mess up where the throttle stops ... causing weird idling and driving issues.
I've been playing with airbox setups so I've been removing/re-installing the MAF tube assembly a lot. I my haste to re-assemble last time, I routed the cables above the valve cover breather hose - I didn't realize the how slight the cruise cable was stressed in the bracket. It was driving fine for until I decided to really nail it and do a hard shift. The engine torqued enough to pull the cruise cable out of the bracket just slightly and held the throttle stuck open just a bit - caused the 'idle' to rev like crazy. I re-routed the cables below the breather hose ... no stress on the cables in the bracket ... and all is well.