I have a 3rz engine in my 1995 Toyota Tacoma that's idling high but it runs totally fine. My previous problem was having low idling around 500rpm at cold starts but would eventually rise up to 650-750 in a little over 5 minutes. I cleaned the maf sensor, throttle body, and iac valve to see if it would get rid of the problem but it just left me with a high idle around 1000-1500 warm. I eventually replaced the IAC Valve because it wasn't operating properly and it got rid of my low cold start idling but now I'm stuck with the high idle. It runs totally fine but my gas mileage dropped since then and the high idling really bothers me. I know its supposed to be around 650-750rpms. Any insight?

 

Any update on this? I just did a 3RZ swap and had a high idle, replaced the IAC and now I have a normalish idle, @850, but I get a thumping sound from the throttle body, sounds like maybe the IAC is cycling and a stutter when accelerating.

 

Just throwing it out there, but do you have a vacuum leak anywhere? and is the cable too tight? there should be some slack in the throttle cable to allow play in the throttle body

 

I still have my high idle but other than that, my truck runs totally fine besides having bad gas mileage.

There aren't any vacuum leaks that I can't suspect but I can check again. And for the throttle cable it has slack, no tension at all.

 

Is it normal to idle around 1000 while its cold and then drop off towards 850?