Hey Guys,

I've owned my 1990 Toyota 4Runner with the 3VZE for a few months now.

Ever since I bought it, I've had an idle issue.

When starting cold, it stumbles for a second or two, and then rises up to a normal cold idle level. A rev when cold causes some some from 1100RPM-2500RPM.

Once warm, the idle drops to 850 where I like it. No stumbling when it's warm.

If the truck is warm, and I stop and get out for more than a few minutes, often times the truck will have a low, loped idle at about 400-500RPM, which either goes away after a few revs, or after driving a couple of blocks.

I did replace the EGR Modulator with a known good that I got for cheap, and I also have a known good EGR valve I'm planning to put in.

The distributor cap and rotor are new, the plugs and wires are not too old.

I don't wanna throw money at the problem, as I don't drive this truck daily, and I've just been slowly wrenching on it now and then.

Oh, and I've searched but haven't found symptoms that match mine, except for one where it was the EGR modulator, which I've replaced.

Your Input is appreciated.

 

I'm on the same boat as you do you have CEL? I've researched a little and throttle body to be cleaned or vacuum lines.

 

No CEL, I've tried to pull codes several times.

 

Oil in your intake?

 

Same engine in mine with similar idle problem. No issues when cold, but once its warm it routinely dies while sitting at stop lights or cruising in neutral (its a manual). Repair book says that idle is not adjustable. Not spending much time/money on it because I'm about to swap in a 4.3L. But I'm really interested in a cheap solution. I was thinking of Seafoaming it and replacing the fuel filter.

 

To me it sounds like a small vacuum leak. check for cracked vacuum hoses ( there are A LOT of them) and to make sure all connections are tight. seafoam is a good idea, I usually put it down the brake tube slowly. fuel filter may not be a bad idea either.

 

I'm going to check for vacuum leaks,

But I think this is sensor related.

then

I'm going to pull and check that the cold start injector is operating properly,

and finally I'm going to pull and check that the ECT sensor port/coolant channel isn't clogged, and put in a known good ECT sensor.

Hopefully I can update this thread with a resolution, as there seems to be few available for this issue.

 

I'm interested in what you find out as well. I've been having similar issues. Usually if Iv'e driven over 30 minuets, stop for groceries, then start it back up it like to idle around 400 and I have to give it some gas to keep it from dying on me.

 

Any update to this?

 

Another vote for vac hose! I've had to change a couple out due to this as well. Take a can of brake cleaner and spray it around the hoses. The engine will idle up when close to the leak. This is how I found mine. Search vac hose leak.... I found the method on here.