low idle

Hey all, I looked through threads and can't find my particular issue. !998 Tacoma that had very fast idle when cold. I replaced IACV and fast idle went away but now idle at startup is maybe 200-400, almost stalls so I give it gas and it remains at 1000 even when warmed up. There is slack on throttle cable. Maybe replace TPS? any suggestions? I also cleaned throttle body and no vaccum leaks. Thank you!

 

Just to clarify exactly what is happening:
1. Had a high idle, "fixed" by replacing IACV.
2. Now it has a very low idle on start up
3. As it warms up the idle increases to 1000 and stays there?

Did you use an OEM IACV or aftermarket?

 

I used aftermarket.And yes to your comments, thanks.

 

You say it 'had' a high idle, but 1000 is still higher than it should be.

Both of your problems, the low cold idle and high warm idle do point to an IACV issue.

From what I've seen the aftermarket IACVs just don't work well for these trucks. It does suck because the OEM ones are admittedly pretty ridiculously priced, but they work much better.

If you still have the original IACV I would fully disassemble it and clean it as much as you can, and reinstall it to see if it fixes it, unless you did that already before replacing it. If you had cleaned the throttle body with the IACV still attached it would have drained all the carbon deposits directly into the IACV.

For other things to look at, if you have a OBD2 scanner, check the throttle position sensor reading, and check the warm steady-state engine temperature.

 

I do have a scanner and will check that, thanks!