I have a 91 pickup 4wd with a 3VZE with a manual transmission, and I have this weird thing happening. When I start it the idle is fine. But when I'm driving, and take it out of gear (either at a stop light, coming to a stop, etc - it's a manual) the engine idles very high. anywhere between 1500 and 2100. BUT if I then hit the accelerator and rev the engine it will drop down to the normal range. It's almost like the throttle is getting stuck, but I don't think that's it?

I just took care of a leaking injector o-ring, and had the upper intake off, but didn't take off all of the hoses. I went back and double-checked that everything was connected properly, and everything was. So not sure what is going on. If anyone has any thoughts I would love to hear them. Thanks a lot.

 

Why not?

Try pulling over when your idle is high, and pop the hood. LOOK at the throttle linkage as you blip it by hand. It may be as simple as a sticky linkage or tired return spring.

 

Yeah, I guess I should. I'll post after I take a look.

 

I’ve got the same issue, not a linkage issue, tried turning idle screw all the way down as well, but it doesn’t even get close to normal idle

 

I wanted to try and get some new attention to this topic. I am still having the issue, and it doesn't seem like a linkage issue from what I can tell. Anyone have any thoughts?

 

Well you have not responded to the suggestion of inspecting it when it's in this high rpm state and you move the throttle under the hood..

Sticky dash pot, cable binding/weak springs, or a worn out throttle plate/body...

 

Check for vacuum leaks...this motor will straight up not run if you're intake is not fully seated etc so it can be very finicky if you have a small vacuum leak somewhere.

What is the timing at idle? Check it with a light if you can.

What have you done recently? Tune up? Plugs/wires/cap/rotor?

If everything is checking out okay you might want to bring it to Toyota and have them diag the TPS (Throttle position sensor). The procedure is in the manual but I have tried it to little success (on me for sure) but it might be quicker and more accurate for toyota to take a look if you're at this point.

 

Thanks for the replies. I did reply about inspecting it at high RPM, and said it did not seem like a linkage issue.

The motor runs fine besides this, so I don't think it's a vacuum issue.

I'm not sure what the timing is, and don't have a timing light. I'll see if anyone has one I can borrow. And I'll also look into the other suggestions. It could be as simple as the spring not having enough tension, but that would be wayyyy too easy of a solution to the problem, which I don't find to ever be the case haha.

It's been so long I don't remember exactly when this started. I had changed the head gaskets, but I don't think it started at that point. I believe I had to remove the upper intake manifold for some reason, and then it started. Once I get some time to take a look again I'll post and let people know what the solution was (if I can find one).

 

A timing light is $30 https://www.harborfreight.com/timing...nce-40963.html . If you're going to do ANY work on your truck, it's probably the 3d or 4th tool you should buy. Get one.

Think how stupid you'd feel if you replaced a bunch of expensive parts, and THEN checked the spring tension. In the end, all problems are easy, some are just easier than others. Start with the easiest ones first, and work your way up to the harder ones.

(for that matter, it's more likely "stickiness" in the linkage than spring tension. Like dirt in the linkage, or a failing cable. All of which are in the "easy" to check category.)