peow130

1998 Tacoma 3RZ 5 speed, etc etc

The idle on this thing seems to have a mind of it's own. For whatever reason, it won't idle below 950, and constantly wants to idle at or around 1100 rpm..

Associated with this is a rough cold start. Cranks over fine, starts fine, just has a tendency to seem like it's about to stall out. Will dip down to like 250 rpm then up to 700 then down and then stabilize at like 1100..

Some days it'll stay at 950, then those same days it'll stay at 1100.

Changed TB to a known clean/good TB. Didn't check the IAC (assumed it was clean).

No CEL's, MAF clean, no exhaust leaks, etc..

Heres a video of what's happening:
http://www.youtube.com/watch?v=IBnJS...ature=youtu.be

peow130

172 Views and no replies.
That's pretty cool.

Cleaned the IACV and throttlebody. Still idles at 950-1000 RPM
If i restart the truck, it'll drop to 750.

It still has the rough start.

ECT possibly? Or front O2 sensor?

Taco-n8

I have a very similar situation with my 3rz...rough idle at cold start and then tends to smooth out after it warms up. I do not have the high idle problem though but it does idle down when i am sitting at a light. I wounder why no one has any advise. Sorry i cant help, if i find out something i will be sure to let you know.

vikkz

hard to say, i had a problem with it not started after it was warm turned out to be a fuel pump. Why dont you try the fuel filter, cheap ($7 or so) and it doesnt hurt to change it. I would check the fuel pressure when the engine is cold see what its doing. Also check all the grounds i remember back when my stepdad had a 92 toyota pick up it took about 3 tries in the morning to turn it on and it turned out to be the ground cable from the fuel injectors.

Not many people got this engine since alot got sold to the dealership for frame rust so it might be the reason why we dont get many responses when we get little problems like this.

Lok47

I had the same problem on my 99 3rz a few years ago and replaced the throttle position sensor and fixed it.

http://m.youtube.com/#/watch?v=bhvsw...%3Dbhvswc_au4M

tantacoma

Could also be a bad IACV, even though you cleaned it.

Remove it and bench test it. The FSM has the procedure, pretty simple.
Just tests if the valve opens or closes when it should.