I rebuilt my 86 4runner 22re engine and bored it .020 over, put an LC engineering RV cam and a set of headers on, an egr delete. I also swapped my auto trans over to a W56 5speed. Well now I have some unusual idle problems. At stop lights it idles up and down up and down. And after a good hour drive it will try to choke off when I come to a stop light. Is there a computer hack or mass air trick I can do to help my 4runner be friends with the new mods?

Also it still has the auto trans computer in it, if that makes a deference

 

I don't know about the computer, but the idle problem you describe sounds like the idle speed is too high. If the idle speed is set too high, when you press the brake pedal, the computer cuts the fuel to the injectors, until the engine is down to the 850 idle it's supposed to be at, and then let's it idle.
If the idle is set too high, it will cycle. Shut off injectors until it's at 850, but the then, because Idle is up too high, when it turns the injectors back on, the idle goes up, so the computer cuts the injectors until it's down to 850, it idles up, the computer cuts the injectors, etc, etc. It's an fuel saving device. You don't need the engine running at any RPM above idle when you're stopping, I believe went the thinking.

Anywho, check to make sure the idle, once it's good and warmed up, is down to 850, as it should be. That often is all it takes to stop this problem. Make sure you use a real tach, external to, and independent of, the truck. Not one included with the truck, if you have one in the instrument cluster. They aren't very accurate down low.

Hope this is a small help.
Pat☺

 

I will check that. It does seem that idle is a little higher than 850. I was thinking that the auto trans computer had a program to keep the idle at a spot when you are coasting in drive, and the 5 speed might be confusing it when I push the clutch in and it goes completely free of the drive train strain