I thought it was an idle issue all along....hehe.

22RE idles rough anyway? Bull...mine has been smooth as butter before. Now, they are known to be a bit chattery with valves and all, but I've been able to get that down substantially with various adjustments. There've been times I could not even tell it was running. This is with 200k + miles on it. It all depends on the health and tuning of the engine.

So, do you mean to say you've been using the dash tach to monitor your idle? It can get you in the ball park or even right on, but it's hard to be accurate with it. A seperate tach is recommended in the manual and others have found it to be more effective. But, if you get the idle where it needs to be using the dash instrument then more power to you. In fact, it's what I'm using presently on my '92...

At any rate, don't mess with a/c idle adjust. just yet. Keep the factors down to a minimum...keep it simple. I would take a paint marker or something to mark where the TB idle screw is set right now. Turn it all the way in until it seats (not to tight) while counting how many full revolutions it makes before it does seat. This will help you keep track of how far you are deviating in your present adjustment. Then, set it back to the original position and just continue to mess with it until you find the adjustment it is happy with. If this doesn't correct it, then begin by readjusting the timing to eliminate the possibility of what 4crawler has suggested....all the while adjusting the idle screw as necessary. If the TB appears to be gummy inside, it would be a good idea to clean it with carb/TB cleaner being careful not get any on the TPS.

Once you've set the idle correctly, you can go back and check your valve adjustments if you suspect they are still a tad off. In fact, many times people do it just as a matter of course.

Incidentally, when checking for vacuum leaks, you ought to use starting fluid instead of brake cleaner. That stuff is very corrosive and will eat things up...like wires and hoses and sensor housings.

 

Thanks for the reply Thook! It is encouraging to know that the rough idle could be fixed. I would love that. Earlier this morning I ran my truck around the block to get it heated up to 190 degrees. I set the idle to run at about 800 using the dash tach. However, On my way to work, I would get to a stop sign and while it was still cold, it would idle really low around 500.

I think I might have another issue. Maybe cold start injector?

Also, when I adjust the main screw on the throtle body to be around 800 when hot, and I turn on the A/C the idle drops way down to about 500. Than I go and adjust the A/C screw to bump up the idle and I can make it go back up to around 900.

However, when I turn the A/C back off, the idle is around 1100. I thought that the A/C screw was not suposed to have an effect on how the engine idles when the A/C is off?

I am confused! Someone please help

 

Check out the A/C idle up valve and the VSV that turns it on and off and the hoses between all that. Might have a leak or a sticking valve that leaves the A/C idle up valve open when the A/C is off.

 

What is the VSV? Do you have a link to how the hoses are suposed to look? How would I fix the sticking valve?

Thanks.

 

Vacuum Switching Valve (basically a vacuum relay):
- http://www.4crawler.com/4x4/CheapTri...ne_Pix/13.html



Clean it out if it is plugged, hook it up right if it is hooked up wrong, replace the hoses if they are leaking, etc.

 

Is the correct idle for a 1991 4runner with 4wd and the 3.0 800 rpm as well?

 

Thank you so much. I will try and clean it/fix it after work.

 

4Crawler, thanks for the picture. I realized the vac lines were switched. When I got out of work and the air temp was at leat 15 degrees cooler than when I had set the idle earlier today, the truck idled at 500 RPM.

Why would it do that?