high idle

M

MtnManx3

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Hi all, my 94 is idling a little high, but I am not getting a check engine light. When it gets good and warm it idles about 1200 and about 1800 until then.....what gives? I am a fairly competent GM wrench, but I should get a code, shouldn't I? I am wanting to buy a Haynes or Chilton manual, but even then I know what they are going to say....just wondering if anyone has had a similar situation or knows a Toyota specific scenario that I may be encountering.

TIA for all help.

Norm
 
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Not sure if it's related, but this summer after driving across the country from Boulder, CO to Burlington, VT, My idle was really high, in the 1200-1600 range. I took it in and turns out the intake butterfly (I think that's what they called it), was all gunked up. They just cleaned and lubed it and it was all better. Must have been all those endless hours at WOT while trying to maintain interstate speeds with 31's and a 22RE, not to mention headwinds.
 
What he's talking about is the throttle plate. It gets gummed up on all cars with fuel injection. Its easy to clean. Take off the hose from the air filter box at the throttle body end. You can now see the throttle plate, maybe an inch back from the edge of the throttle body. Take a clean, lint free rag and some carb cleaner and clean out the inside of the throttle body. Pivot the throttle using the accelerator linkage and clean under the edge of the plate.
BE REAL CAREFUL not to get any carb cleaner into the throttle position sensor attached to the throttle body as it will eat up the printed circuit in there and cause problems.
It takes about 5 minutes and you save yourself a chunk - some places charge 70-100 bucks for this simple chore.
 
ultrabongo said:
What he's talking about is the throttle plate. It gets gummed up on all cars with fuel injection. Its easy to clean. Take off the hose from the air filter box at the throttle body end. You can now see the throttle plate, maybe an inch back from the edge of the throttle body. Take a clean, lint free rag and some carb cleaner and clean out the inside of the throttle body. Pivot the throttle using the accelerator linkage and clean under the edge of the plate.
BE REAL CAREFUL not to get any carb cleaner into the throttle position sensor attached to the throttle body as it will eat up the printed circuit in there and cause problems.
It takes about 5 minutes and you save yourself a chunk - some places charge 70-100 bucks for this simple chore.
Click to expand...

Awesome, I will give it a shot.
 
Well, I pulled the air intake boot off of the throttle body and it was much cleaner than I imagined it could be. But I gave it a wipe down anyway, and put it back together. No change in idle performance.....I tried to inspect for vacuum leaks, but everything looks good.

Since it seems to be engine temp related, I wonder if maybe like the coolant temp sensor or something is causing it to run in like a closed loop scenario??? It never comes down below 1200 ish, even when it has been running for 30 minutes or more. :confused:
 
manual suggests as follows for high idle: check-accelerator linkage, ignition timing, air valve, fuel pressure, cold start injector, water temp sensor, ( thats the unit you're calling coolant sensor) air flow meter, air temp sensor, injection signal.
You might need to get a manual and use an ohmeter to figure it out. I would try checking one thing at a time in the order they give above.
It could be the coolant sensor, but when I've had bad ones the idle wasn't off that dramatically.
Good luck with it.
 
ultrabongo said:
manual suggests as follows for high idle: check-accelerator linkage, ignition timing, air valve, fuel pressure, cold start injector, water temp sensor, ( thats the unit you're calling coolant sensor) air flow meter, air temp sensor, injection signal.
You might need to get a manual and use an ohmeter to figure it out. I would try checking one thing at a time in the order they give above.
It could be the coolant sensor, but when I've had bad ones the idle wasn't off that dramatically.
Good luck with it.
Click to expand...

I am happy with the linkage, and timing. What is the air valve? I replaced the cold start injector, but no help. I am probably going to replace the temperature switch to the cold start injector and see if that helps.

For now, the only fix I have found is to turn the idle screw most of the way inward. It is only turned out about 1 and a half turns, and I don't think that is right. Can someone tell me how many turns out theirs is?
 
throttle

Ours is doing the same thing. Try putting a 3-second spray of WD-40 onto the throttle. The throttle might be sticking to the body. :awais: :bash: ;):
 
The air valve is also temperature sensitive, allowing increased air to the engine when cold to promote idle. The air passage in the air valve is controlled by a bimetallic spring, gradually closing as the engine warms.
Its got 3 hoses to it- 2 air, one water. If you pinch one of the air hoses shut
with your fingers when engine is running cold, RPM should drop noticeably. Pinch the hose that runs up into the throttle body.
Also check resistance with an o-meter. Should be 39-59ohms.
 
Hi there, hoping to revive this forum as I'm experiencing similar problems with my 1991 3.0 V6 3vZe.

Just seeing if the issues were eventually resolved with your 94 in order to start the process with mine. I'd rather not throw parts at this problem to keep the cost down, if at all possible.

I live in a winter climate and don't have a workshop therefore I'm paying to have the work done at a local garage. Truck is in good working order, has
130 000 KM's (80 000 miles or so), timing belt and water pump have been replaced by Toyota on warranty due to the water pump seals going bad before i bought the truck. I'm the second owner but the truck was very well maintained by the previous. truck was running impeccably until about 1 year ago when the fan clutch went, it has been replaced but since then I've noticed gas mileage has become horrible.

Truck is idling at about 1200 rpm after warmed up, and guzzles through a full tank of gas of roughly 60L in 320 KM's! (15 gal in 200 miles).

Upon first inspection the mechanic said that temperature was checked on the hoses and heat is good so he does not suspect the thermostat is the issue. also the throttle body was inspected and looks clean and in good working order. mechanic said the adjustment screw is capped from the factory and he does not think removing the cap and making adjustments is a good idea.

he said the next step might be replacing the throttle body but finding a new one is not easy and buying used doesn't inspire much confidence as most of the ones in eastern Canada are rusted to shit.. wondering what to do next?

Truck is in excellent shape and would love to keep it running if possible :(
 
Keep engine running with air intake hose removed

Hi there from New Zealand. New to this forum thing - but long time reader! Just wondering if anyone knows how to keep the engine running when the air intake hose has been removed (it automatically shuts off if you remove the hose). I remember reading ages ago that there was a way to bypass it by using the terminals. Any ideas? Cheers. BTW Engine is 3VZE.
 
levonhelm said:
Hi there, hoping to revive this forum as I'm experiencing similar problems with my 1991 3.0 V6 3vZe.
Truck is idling at about 1200 rpm after warmed up, and guzzles through a full tank of gas of roughly 60L in 320 KM's! (15 gal in 200 miles).


I am in the same boat, but my gas mileage is a little worse...did anyone find any fixes. I also cleaned my throttle body and no help.
Click to expand...
 
+1 for the throttle plate. Open everything up and give it a look. I’ve had vac lines crack but never had an increase in idle.
 
Have you checked your throttle cable? Maybe it’s binding and not going through full range of motion. How long has problem existed? Any changes to temp out side? I know my 93 would idle high around 1200-1500 during start up in cold mornings. I never noticed anything else to be wrong with it
 
Well mine has done is since I bought it and that was during the summer. I didn't really think it was an issue till I read about what other people's trucks idle at. on a cold start it idles at 2000 and when warm idles at 1200.
 
Update: (3VZE with high idle and horrible gas mileage)

I've changed the air filter, the distributor cap, the plugs, cables, fresh oil change and replaced the muffler (since it had a giant hole in the bottom) but the truck remains at 1200 rpm even when warm. I've noticed the idle is never really smooth, doesn't jump around much but it fluctuates a tiny bit.

After eliminating all those possibilities I moved on to the throttle position sensor:
found the threads relating to that fix and got busy checking resistance with the feeler gauges and an OHM meter. It seemed like the T.S.P. might be ever so slightly in need of adjustment. I shifted it until all the numbers were in the middle of the ranges given in the service manual. all is well but truck still idles at 1200???!!

Talked to some mechanics with 10+ years experience I was told to look at cleaning the MAF (mass airflow sensor), found write ups on the forum indicating that the 2nd gen 4 runner does not have one, we have a Vane sensor and "cleaning it" is more likely to damage it.

Opened up the throttle body and everything is clean as a whistle.

Disconnected throttle cable completely, idle did not change.

After that I moved on to the Idle screw adjustment which I gradually adjusted until my idle finally went down to 600-800 when warm. the truck starts cold and idles at about 1100 and then drops down slowly to 800 ish but I feel like adjusting this screw was a band aid solution to a problem that I haven't found yet.

My idle still jumps around once in a while, my gas mileage is still horrible compared to what I've read. i'm staring an injector treatment today but i'm at a loss here...

fuel filter next?

(I've checked the wiring and battery output on this truck and everything is up to snuff)
 
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The symptoms you mention sure point to a vacuum leak. And with all the hoses these motors have, it could be anywhere! One of the first things I did when I bought my 94 was to change all the vacuum hoses. Not that expensive, our rigs are getting old and that rubber doesn't last forever! Hope it turns out to be that simple. Rod
 
Same thing is happening to me... Only thing that is weird is that I Replaced all my vacuum hoses with a kit from LCE Engineering and still the problem persists... Im at a loss as well.
 
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