Im soo sick of this issue! Ive done all i can just so this stupid idle dipping up and down problem would go away but noooo!!! I did the following hoping it would go away..
*UIM/LIM Cleanup
*New IAC
*Cleaned MAF
*TH Fix (i dont think that had anything to do with it)
*New TPS
now there are no vacuum leaks at all, or that i know off..However one concern i do have, upon installing the new TPS, I didnt callibrate it or anything, is that why maybe my idle is still bad? if so what can I do to fix it? thanks
Hello,
I think I have the same problem on my 96 Zetec.
The RPM goes from 800 to 400 every 2 seconds.
I need a fix.
The TPS requires no calibration .
Fluxuating idle is almost always a vacuum leak.
The O2's would have to be terrible to cause it.
If you installed new gaskets on the LIM, UIM, TB, IAC, and EGR valve - pull the top two lines and plug them. If that's not it, give the PCV valve and hose to the intake a good inspection (or plug the intake port). The formed elbow often gets soft and leaks or collapses.
If you still have a problem, spray the UIM end plugs with carb cleaner for a test.
I have the same issue with my 96 contour. I havew changed the MAF, Cleaned the IAC, Fuel Filter, Air filter, Checked countless items.
I was wondering what the gasket looked like when you installed the new IAC. Was it like 2 O rings or was it a big gasket covering the entire mating surface?
I also was wondering if you checked the spark plugs I have heard this suggestion many times.
I just fixed my idle problem( I hope) with cleaning out the IAC and installing a new figure 8 gasket. I also found that the fat O ring on the bottom of the plenum chamber was not seated right and probably caused an air leak between it and the throttle body. You may want to check the fat O ring. Did you install a new gasket with IAC as well?
The O ring was at the bottom of the plenum chamber and on top of the throttle body, it had nothing to do with the IAC. However you should have replaced the figure 8 gasket that is located between the IAC and engine. Did you replace that? that was all I replaced on my car and just cleaned the IAC because couldn't find new one for under 110 dollars.
Hope you used a Ford IAC also.
Sure you got the right tps? I know autozone didn't have the right one in their computer a couple years ago when I needed to replace mine. Not sure if our cars have two fluid temp sensors but I did some work on my truck which has two and one wasn't hooked up and I had a bad idle sitiation. Once it was fixed it ran perfect.
Could it be his fuel pumpfreakin out from bad voltage comingfrom a bad alternator?
Goonz,
I am having these same problems. Did you ever get it fixed?
It was sputtering while turning? Sounds like a vacuum leak. When you're turning, the engine ups the revvs a bit to accomodate the power steering. I bet somewhere in your CAI is the problem (mine too)