Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
2000 Tacoma 2.7 4wd 2 door extended cab high idle condition no codes present. Hi my name is Isaiah I recently got a job offered in Alaska and need to make the drive from Oroville California to fairbanks Alaska in two weeks from now I leave may 27th and my truck is giving me issues yikes. I recently installed a new cylinder head on my truck because it had a burnt valve and it seemed to run okay other than having a little higher than normal idle at around 1,000 RPM. I pinched off the hose to the IAC to see if the idle would drop and it seemed to drop to 750 rpm which would be ideal. I proceeded to replace the IAC and cleaned the throttle body while it was apart and when I went to fire it up the idle was even higher than before at 1,800 rpm at some times. I monitored fuel trims and they were close to 0% and the engine coolant temp data seemed to be accurate. The IAC duty cycle was at 23% and when I pinched off the line to the IAC this time it dropped maybe 50rpm but nothing significant. Now my understanding this is a MAF only engine and if there were a vacuum leak it would have the oposite effect and have a lower rpm or not run at all. I have checkd the throttle body and the linkage does not seem to be hanging up and I have adjusted it as low is it can go. It almost seems to me that maybe the throttle body itself was worn and cleaning the old carbon may have shown this new issue? I cant find any info on Prodemand on a possible relearn procedure for anything is there even one for these Toyotas? I would really appreciate some insight I am early in my career as a mechanic and have a wonderfully apprenticship opportunity waiting for me but I have to be able to make the drive very urgent thankyou.
Last edit: 2 days 3 hours ago by IsaiahC. Reason: Missing technical info
I agree that a MAF equipped engine should idle low and have high fuel trims if there were a vacuum leak.
If the issue started after the head job, I would want to double check the timing. Does this have a pressure switch for the power steering that could be holding the idle up? Or a vacuum actuated fuel pressure regulator that could be leaking fuel into the engine?
It could also just be a faulty IAC since it got worse after you cleaned it.
