highway

this is on a '89 22re 4x4 truck. My idle is around 1200 rpm's i adjusted the screw @ the throttle body all the way in and that is as low as it will idle. today i adjusted the valves and set the timing @ 5 degrees. i cleaned the throttle body plate real good and sprayed carb cleaner trying to find a vacumn leak but could not find one. A couple weeks ago i replaced the PCV valve with one from napa and i replaced the thermostat with a stant brand and come to find out that's the same brand t-stat that was installed......could a bad t-stat cause high idle ? Every once in a while the idle does surge up and down.

highway

rdlsz24

Is this cold idle, or hot idle? I ask because it will idle higher when cold. My 22RE idles at about 2k when stone cold, and I have it set to idle at around 1k at normal temp. The extra rpms make it idle a little smoother.

Rob

highway

yes this is at hot idle, the engine runs around 2K when cold warming up

highway

highway

anyone ?

Robrt32

I got something similar going on with mine, get this.... Whem i press my brake with the clutch pressed down my motor idles up and down . When i take my foot off the brake , she purs like a kitten.. I have traced all my brake light wires looking for a short .. I'm bumfuzzled on it

jimwww

After it is warmed up seems to idle at 1400 rpm.. not sure why - but I do need a new exhaust.

ovrrdrive

Mine just started doing this last weekend. I was sure it was the dash pot so i started spraying wd40 on it, and then I sprayed some PB blaster on it and that helped a little after it soaked in for a day, but I was still idled up too high.

On a recommendation from titicaca to check to see if it would drop if I pushed in the dash pot with a screwdriver, I noticed that it would stay idled up until I took my hand and manually closed the throttle. Bingo, it was the butterfly in the throttle body sticking.

I sprayed some PB Blaster inside the end of the TB with the hose off and made sure to get it on both hinges of the butterfly and then I wiped all around as much as I could and tried to wipe with the throttle cracked too to make sure there wasn't any trash in there holding the valve open.

On first impressions it looks like that fixed it. I won't know for sure though until I drive to work tomorrow.

ovrrdrive

Robrt32, your problem is one of the most common problems to ever grace the forums.

Search for fluctuating idle and you'll get several days of reading.

I just made a thread a few weeks ago about it and following leads from 4crawlers page I was able to narrow down the brake lead to my ECM and cut it which completely solves the problem forever.

If you don't want to do that though just start adjusting your idle down a little. It only happens when the idle is too high and the AC idle up kicks in with the brake pressed. Between adjusting the idle screw, and the idle up valve you can work this problem out but it will come back everytime the weather changes.

Here's a link to my post:

https://www.yotatech.com/forums/f116/fluctuating-idle-ac-brake-pressed-definitive-fix-103923/

Robrt32

Thanks, I have worried with this off and on for 2 years, I just idled my motor down and it fixed it!!!! THANK YOU... I am glad i have found this forum!!!

Thank you all