High Idle issues
#1
High Idle issues
I replaced a blown headgasket caused by overheating due to a broken alt belt and me not remembering that the alt belt also runs the water pump. Oops! Any mating surface taken apart received a new FelPro gasket.
At some point during the process I cleaned the TB but forgot to remove the TPS first. I realized it while I was spraying TB cleaner and immediately wiped everything out. Didn't think I got any in there anyway and forgot about it. Now that everything is back together the truck runs extremely well with lots of torque.
TRUCK:
1985 Pickup SR5, 22RE, 5 spd, 4x4, deleted A/C, PS (from 3rd gen 4runner), 452k kms (280k mi), ~35k kms (22k mi) on rebuilt motor, ~6000 kms (3700 mi) on rebuilt W56 transmission. Used primarily for rock crawling, work around the property, and somewhere around 1000kms (625 mi) of highway driving in a month.
When the truck was back together and the high idle presented itself, I removed the TB and adjusted the TPS after reading 4crawler's guide. I used a reliable multimeter and adjusted its position until everything was within the FSM specs:
#1) VTA-E2 (@0.000") = 669 ohms (spec = 200-800)
#2) IDL-E2 (@0.0224") = 13.5 ohms (spec = <2.3k)
#3) IDL-E2 (@0.0335") = OL (spec = OL)
#4) VTA-E2 (@WOT) = 4.831k ohms (spec = 3.3k-10.0k)
#5) VCC-E2 (@N/A) = 5.336k (spec = 3.0k-7.0k)
This leads me to believe that the TPS is fine, correct?
WHAT I'VE DONE:
(1400rpm idle, rough idle, low power, poor fuel economy)
-Throttle cable and linkage move freely.
-No dashpot.
-Replaced thermostat with Motorad/Murray dual stage 414-192, same as old one. Old one seemed fine and was only two years old, but I wanted to be certain after overheating.
-Coolant full with no air bubbles. Blower produces hot air.
-Cleaned & tested IAC. The bimetal spring and rotating block off plate moved freely, and the little coil spring kept them in good contact. The airway was only partially open when cold (maybe 25%) but if anything this would cause a low idle, right? Also cleaned out the coolant ports (they were quite clean already).
-Adjusted valve lash. I had done this earlier on a cold motor using 0.007" & 0.011" clearances, which has worked well for me in the past. This time I did it exactly as per FSM. Hot motor; 0.008" IN & 0.012" OUT.
-Replaced spark plugs (NGK BPR5EY) gapped to 0.031". Old ones were the same plugs, had 18.7k kms (11.6k mi), dry, light brown.
-Metal connector inside #3 spark plug boot was pulled back 1/4" causing poor contact. Maybe I pulled it off by the wire, idk.
(1300rpm idle, smooth idle, more power, no hesitation)
-Test drive: much better than before, but still idles high.
-Set timing to 13° on hot motor with diagnostic connector jumped. I had wanted to get the idle set correctly first but was curious if this would improve anything. Idle now sits at ~1300rpm w/ adjust screw almost fully closed.
(1000rpm idle, smooth idle, lots of power throughout rpm range)
-Test drive: Very happy with the results! I guess I effectively gave it a decent tune-up. Idle now sits at 1000rpm, but I'm happy with everything else.
-Hunted for vacuum leaks with a variety of methods but found nothing. Using 1/2" hose as a makeshift stethoscope, using MAP gas, and spraying joints with TB cleaner.
The idle is still high with the idle adjust screw fully closed. The only way the motor should be able to get air would be through the butterfly valve (closed), idle adjust screw (closed), and the IAC... right? So, I blocked off the IAC port inside the TB with foil tape. With the port blocked it idles around 600rpm so this indicates the IAC is bad or still blocked, right? Except I just remembered the idle adjust screw was fully closed. Air leak then? What? Any ideas on how to narrow it down? Is it both? I'm obviously missing something and I've tried all my ideas.
Any help is greatly appreciated!
At some point during the process I cleaned the TB but forgot to remove the TPS first. I realized it while I was spraying TB cleaner and immediately wiped everything out. Didn't think I got any in there anyway and forgot about it. Now that everything is back together the truck runs extremely well with lots of torque.
TRUCK:
1985 Pickup SR5, 22RE, 5 spd, 4x4, deleted A/C, PS (from 3rd gen 4runner), 452k kms (280k mi), ~35k kms (22k mi) on rebuilt motor, ~6000 kms (3700 mi) on rebuilt W56 transmission. Used primarily for rock crawling, work around the property, and somewhere around 1000kms (625 mi) of highway driving in a month.
When the truck was back together and the high idle presented itself, I removed the TB and adjusted the TPS after reading 4crawler's guide. I used a reliable multimeter and adjusted its position until everything was within the FSM specs:
#1) VTA-E2 (@0.000") = 669 ohms (spec = 200-800)
#2) IDL-E2 (@0.0224") = 13.5 ohms (spec = <2.3k)
#3) IDL-E2 (@0.0335") = OL (spec = OL)
#4) VTA-E2 (@WOT) = 4.831k ohms (spec = 3.3k-10.0k)
#5) VCC-E2 (@N/A) = 5.336k (spec = 3.0k-7.0k)
This leads me to believe that the TPS is fine, correct?
WHAT I'VE DONE:
(1400rpm idle, rough idle, low power, poor fuel economy)
-Throttle cable and linkage move freely.
-No dashpot.
-Replaced thermostat with Motorad/Murray dual stage 414-192, same as old one. Old one seemed fine and was only two years old, but I wanted to be certain after overheating.
-Coolant full with no air bubbles. Blower produces hot air.
-Cleaned & tested IAC. The bimetal spring and rotating block off plate moved freely, and the little coil spring kept them in good contact. The airway was only partially open when cold (maybe 25%) but if anything this would cause a low idle, right? Also cleaned out the coolant ports (they were quite clean already).
-Adjusted valve lash. I had done this earlier on a cold motor using 0.007" & 0.011" clearances, which has worked well for me in the past. This time I did it exactly as per FSM. Hot motor; 0.008" IN & 0.012" OUT.
-Replaced spark plugs (NGK BPR5EY) gapped to 0.031". Old ones were the same plugs, had 18.7k kms (11.6k mi), dry, light brown.
-Metal connector inside #3 spark plug boot was pulled back 1/4" causing poor contact. Maybe I pulled it off by the wire, idk.
(1300rpm idle, smooth idle, more power, no hesitation)
-Test drive: much better than before, but still idles high.
-Set timing to 13° on hot motor with diagnostic connector jumped. I had wanted to get the idle set correctly first but was curious if this would improve anything. Idle now sits at ~1300rpm w/ adjust screw almost fully closed.
(1000rpm idle, smooth idle, lots of power throughout rpm range)
-Test drive: Very happy with the results! I guess I effectively gave it a decent tune-up. Idle now sits at 1000rpm, but I'm happy with everything else.
-Hunted for vacuum leaks with a variety of methods but found nothing. Using 1/2" hose as a makeshift stethoscope, using MAP gas, and spraying joints with TB cleaner.
The idle is still high with the idle adjust screw fully closed. The only way the motor should be able to get air would be through the butterfly valve (closed), idle adjust screw (closed), and the IAC... right? So, I blocked off the IAC port inside the TB with foil tape. With the port blocked it idles around 600rpm so this indicates the IAC is bad or still blocked, right? Except I just remembered the idle adjust screw was fully closed. Air leak then? What? Any ideas on how to narrow it down? Is it both? I'm obviously missing something and I've tried all my ideas.
Any help is greatly appreciated!
Last edited by Meatbag; Dec 15, 2023 at 08:51 AM.
#2
https://www.yotatech.com/forums/f116...6-22re-189429/
I found this link, it's regarding an 86- I think the timing is set to 5° btdc. I have an 84 iirc that is what my 22re is set at.
I found this link, it's regarding an 86- I think the timing is set to 5° btdc. I have an 84 iirc that is what my 22re is set at.
#3
https://www.yotatech.com/forums/f116...6-22re-189429/
I found this link, it's regarding an 86- I think the timing is set to 5° btdc. I have an 84 iirc that is what my 22re is set at.
I found this link, it's regarding an 86- I think the timing is set to 5° btdc. I have an 84 iirc that is what my 22re is set at.
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