How to fix high idle?
02-02-2009, 08:28 PM
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How to fix high idle?
I just took off my intake manifolds,(3rz) and throttle body. I cleaned out all the crap the EGR dumps in there, and re-assembled it with new gaskets. I also installed a cold-air intake. Now it idles at around 1600-1800 rpm....is there a way to adjust the idle....? I know to check(but haven't yet) for vacuum leaks and such, but do you think the ECU needs to be reset for the extra air flow from the cold air intake install? If so how? Other than un-hooking the battery for a while?
02-02-2009, 09:08 PM
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is there no idle control screw on the 3rz's throttle body?
Perhaps by cleaning all the junk out of there, its able to breath better, and before the idle was adjusted to accommodate the gunk. ya follow?
Or perhaps you didn't hook up a vacuum hose in the right place.
I have no experience with the 3rz, so I can't say for sure
Perhaps by cleaning all the junk out of there, its able to breath better, and before the idle was adjusted to accommodate the gunk. ya follow?
Or perhaps you didn't hook up a vacuum hose in the right place.
I have no experience with the 3rz, so I can't say for sure
02-03-2009, 02:21 AM
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As you look at the throttle body from the front of the vehicle, there is a flathead screw for HOT idle adjustment, inset into the throttle body.
02-03-2009, 09:25 AM
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It sounds like you either have a vacuum leak or some vacuum lines misrouted when it was reinstalled.
Take some carb cleaner and spray around vacuum lines and ports and if it makes the idle speed drop in rpm, then you have found the vacuum leak.
It's running at a high idle speed due to the lean condition caused by extra fresh air being entered into the system that is not being managed by the MAF sensor and intake.
Take some carb cleaner and spray around vacuum lines and ports and if it makes the idle speed drop in rpm, then you have found the vacuum leak.
It's running at a high idle speed due to the lean condition caused by extra fresh air being entered into the system that is not being managed by the MAF sensor and intake.
Last edited by 99SC4Runner; 02-05-2009 at 11:19 AM.
02-03-2009, 10:11 AM
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02-03-2009, 10:33 AM
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Alright...I checked every bolt, went over the vacuum lines twice..all good. Took it for a test drive and the rev's drop down when I press in the clutch to stop, but they go right back up to 1500. Also, on a cold or cool start, the revs are low, then gradually rise to 1500. There is no flathead screw on this throttle body. I messed with the set screw that keeps the throtle plate from closing all the way and that maybe got me 50 rpm lower.....Also during the test run I noticed that the damn oil light came on. I changed the sensor the other week, hoping that was it, but looks to me like the friggin pump is going.....
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02-03-2009, 10:34 AM
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Thats why you can't find this idle speed control screw. I don't know where it is, but I would be glad to go look on my roommates '96 if you need and no one chimes in soon.
02-03-2009, 10:34 AM
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How could the MAF not manage it...it all passes through it on the way to the throttle body right?
02-03-2009, 10:38 AM
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Alright...I checked every bolt, went over the vacuum lines twice..all good. Took it for a test drive and the rev's drop down when I press in the clutch to stop, but they go right back up to 1500. Also, on a cold or cool start, the revs are low, then gradually rise to 1500. There is no flathead screw on this throttle body. I messed with the set screw that keeps the throtle plate from closing all the way and that maybe got me 50 rpm lower.....Also during the test run I noticed that the damn oil light came on. I changed the sensor the other week, hoping that was it, but looks to me like the friggin pump is going.....
02-03-2009, 10:54 AM
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Never touched or loosened the TPS, but I just went outside, unhooked the connector for the I.A.C valve, fired it up and the revs were at 850 or so. I also got an immediate CEL....while it was still running I hooked the I.A.C valve connector back up and lo and behold back to 1500! I don't know.
04-14-2010, 01:51 PM
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I have the same problem with my 2002 5vz!!!
When we scanned the truck it showed a throttle input of 9% even at idle.
My IAC valve is open probably 15-20% when I took it off, is that normal? or should it be totally closed?
When we scanned the truck it showed a throttle input of 9% even at idle.
My IAC valve is open probably 15-20% when I took it off, is that normal? or should it be totally closed?
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