Erik Beeman

Truck is a 92 22RE, new motor has 3K on it. Problem started after rebuild and motor was put in.


Truck has a funky idle during warm up. This happens everytime the truck is cold, and only does it until it reaches a certain temp., usually running temp. It will revv high, then drop, revv high, then drop, revv high, then drop, etc. The warmer it gets, the slower it happens. For example, when it's cold, it will REV DROP REV DROP...then as it gets warmer, it REVVV.....DROP REVVVV....DROP, then when it's almost warmed up, it REVVVVVV...........................DROP REVVVVVV........................DROP. Then once it reaches operating temp, it smoothes out and idles fine.

I have a check engine light on, it's my EGR. The vacuum is disconnected. At first, I thought this was the problem. So I reset the ECU and reconnected all vacuum lines, and it still does it.

Any ideas? Faulty ECU? I can take a video with sound of this if anybody wants.

fnrunner

part of it could be that the TPS sensor is either bad or just out of adjustment. search around here or on Roger Brown's site for details & how to.

qdude79

IsIsis the vac line to the egr plugged? If not, you have a vac leak that is being exaggerated during warm up. Idles probably pretty high too, right? When it warms up, cold start injector kicks off, idle air control valve closes, less air, less vac leak.

whokrz

I think something is hooked up incorrectly or out adjustment. I would get your egr working correctly so that you do not have a engine light on. It could also be a vacuum leak somewhere that pushes it over the top when it is cold. There is a air bypass under the throttle body that opens when the engine is cold.
I would guess that the slowing of the loping is caused by air bypass closing and when it is finally closed the engine is able to compensate for the vacuum leak.
There is a link to FSMs in my sig that you may also find useful.

Erik Beeman

What could the TPS sensor have to do with it on warmup? I've checked it many times since the motor has been in because I had a different problem that I thought involved the TPS.

EGR, is disconnected, but is plugged. The EGR valve itself is not, but the vacuum line is. And like I've said, I've reset all codes and plugged EGR back in, and there was no difference.


What is this air bypass that you are talking about under the throttle body?

Junkers88

This is the valve he's talking about.

Erik Beeman

Ok.


So, when the truck is cold, I can turn that idle adjustment screw all the way in, and this fixes the problem. It drops the RPMs down and there is no idle surging, but as soon as the motor is warm, it won't idle. I have to open the screw back up, or it will die because there is no air.

Now, this is as far as I can get with my knowledge, but I do know there has got to be someone on here that can take the information I just gave and lead me in the right direction. Vaccum leak? I tried finding one but can't find anything.

fnrunner

I shouldn't have commented on this...now mine is doing this too. Figures. Mine does it all the time though...hoping the TPS is just out of adjustment again...


Sorry, I'm no help.

TTT for our friend in need...

Erik Beeman

...as in, it's happend before?

fnrunner

Well, yes. Unless it was just never properly adjusted by the previous owner. I made some adjustments to it about 4 yrs ago & all has been good till now. So now when I do the 2 tests involving the 0.022 & 0.033 feeler gauges, I get infinity, or open...after making some small adjustments it is still not working properly. I'm guessing since it's a Toyota part, that it's an '85 original. Cause the P.O. would have never put on OE replacement parts, so it's contacts are probably burnt. I've called all over & best I could find was $165 @ O'Reilly's w/ lifetime warr. - ouch! My 3.0L's was only $103 5 yrs ago...and that was OEM from TRDparts4U. We'll see what they come back at on this one.

fnrunner

Just checked my email & they have it for $146 plus s/h, but they're out till Monday. :/
crap. O'Reilly can have it tomorrow @7:30...

Sorry...hi-jacking over...

fnrunner

Hey Beeman, any updates? What fixed your problem??

Mine's still givin me fits.

Junkers88

fnrunner,

Somthing else you may want to check is the little O ring around the idle adjustment screw. Mine was bad and the idle would move around on it's own. I changed out that screw with one from my trail spare throttle body (with a better O ring) and the idle is stable(er). When that O ring goes it creates a controlled vacuum leak, that leak is behind the AFM and TB so it is unmetered air. Could cause some issues. I know mine used to idle at 2000rpms cold before the screw swap and bounce around a bit as it warmed up. Now it idles at 1500-1700 and doesn't bounce nearly as much. I'll be buying a new O ring and swapping it in here in the next few days since there is probably still a little controlled leak with the newer/less old one.

toyota4x4907

Is the coolant full and free of air pockets?