High Idle

[99_RRdifflock]

Another Q.

My Runner seems to like idling around 1K. Sometimes it goes down to just over 700, but usually around 800-900, and sometimes just decides to go higher back to 1000-1100 sometimes I stop. Sometime, if it is idling high, and I rev it (while stopped) to 5000, when it comes back down, it is around 700. Is this a dirty MAF thing? Throttle position sensor? Should I pull the EFI fuse out for an hour or so?

I did do the intake silencer removal mod, and the deckplate mod, and did not pull the EFI fuse out (some recommend it). Any thoughts?

Thanks,

 

[infantry503]

That's doesn't seem to be a high idle to me. When I got my 4runner it was idling at around 1600 rpm and I got it bumped down to 1100 by cleaning the MAF and just for good measure I replaced the IAC

 

[thecole1098]

Spec for these is 650-750 in drive and 750-850 in park. Typically the cause of high idles on these are either dirty or bad Idle Air Control Valves, which is located below the throttle body. Simply spraying throttle cleaner in the throttle body will not be enough to clean the IAC. You will have to remove the throttle body and actually remove the valve to properly clean it. Remember to start simple first and check your throttle cable to make sure it's not too taught.

Be sure to pull your EFI fuse under the hood for 15-30 mins after cleaning the IAC.

 

[19963.4lsr5]

I have removed the throttle body to clean the IAC and I've also sprayed sensor safe throttle body cleaner into the IAC's air port without removing the throttle body from the intake.


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[Nate_GB]

Check for loose or cracked vacuum hoses. Could be a vacuum leak. There's a few different way to verify if you have a vacuum leak. Just google around and you'll find them.

 

[pluton]

My '97 had high idle disease when I acquired it in 2013. I didn't feel like taking the TB off of the top of the engine since it was new-to-me truck and unfamiliar to me. I could make the idle normal by forcing the throttle valve to close all the way by holding it closed by hand. I dumped it on the dealer, who replaced the TB and used up my bumper upgrade money in the process.
The new TB came with a new IAC valve and TPS. So the issue could have been with the IAC valve, but I recall that the throttle valve was definitely not closing all the way. I'm sure that the throttle valve mechanism could have been jury-rigged or modified to eliminate the high idle without going through the trouble and expense of total replacement, but I wanted it nice and sano for the long term.

 

[PipoToyo]

Idling High Fixed

My 4runner was leaking oil around the crankshaft moons and half moons so I spent the afternoon changing valve cover gaskets and sealing everything up. Also had high REV even after sea foam so I took throttle body and IAC apart and cleaned them well. The engine was revving higher after all the work and nothing I read here and tried workedb to fix it. So I was on my way to Toyota to get an IAC and one last attempt to diagnose it fixed it. The gas cable adjustment on the throttle body seemed just a tad loose so I loosened it up and snugged it up three turns on the adjustment nuts. No more high revving in park, neutral, reverse or when coming to a stop. Idles at 750 range like a kitten.

 

[YodaFoRunna]

I've done two tacomas with the 3.4L with high idles. TPS was the culprit. Both were idling around 1k RPM

 

[FnM1998]

My 99 has the high idol too, we have swapped out the throttle body cleaned it and still high idol! Help!!!