High idle issues
High idle issues After getting my car tuned I was advised to shave a little off my throttle blade. It was hanging up a little bit. After reinstalling when I start the car it revs straight to 3k+ and holds there. Any ideas it ran perfect all I did was bring the blade a little. Not nearly enough to cause a 3k idle
Heads cam full bolt ons. The part that's weird is it ran fine. I adjusted the throttle blade (shaved a little off because it was catching) reinstalled and idles went ape **** on me
Launching!
Joined: Jun 2005
Posts: 277
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From: SC
Just a guess from working on my archaic system, don't know what you are working with or if this is even applicable:
Maybe a combination of two things....
IAC at open position for air flow it needs to start.
Extra flow from the modified butterfly.
Now when starting the idle goes up past the cutoff for RPM follower so that the computer does not try to close the IAC valve. I.E. my system you set the TPS position and RPM you want the computer to be able to control RPM's. The problem with that is once you go higher than that RPM the computer does not try to control the IAC. So, if you've got your foot off the gas but the butterfly position is such that enough air can get in and keep the RPM's from coming back down to the turn on point it'll just sit there.
Maybe a combination of two things....
IAC at open position for air flow it needs to start.
Extra flow from the modified butterfly.
Now when starting the idle goes up past the cutoff for RPM follower so that the computer does not try to close the IAC valve. I.E. my system you set the TPS position and RPM you want the computer to be able to control RPM's. The problem with that is once you go higher than that RPM the computer does not try to control the IAC. So, if you've got your foot off the gas but the butterfly position is such that enough air can get in and keep the RPM's from coming back down to the turn on point it'll just sit there.
Confirm that the throttle isn't sticking and hanging open a fraction. Check your throttle position sensor because there may be a chance that why you remounted the throttle blade, it is offcenter a hair, and hanging it open at like 1-3%, which is enough to cause a 3,000 rpm idle.
