1uzfe IACV idle problems

[Brennan]

i have a 1991 1uzfe soarer that is doing some strange sh*t, just wondering if somebody on here can offer something we haven't thought of/looked at.

 

when i got it, the Idle control valve was stuck open. so the fresh air line to it, was blocked off.

This meant it was dificuilt to start/drive when cold, as it wouldnt hold any revs.

 

I brought some bearings and rebuilt it. 

 

it took a while to set it back up again after rebuilding it (not to open, not to closed)

 

but i was pretty sure i had it sorted last night, idling around 600 while warm.

 

Started this morning first go, idling around 600, so was happy with that as it was a rather chilly morning.

At 12 i drove to get some lunch on the other side of town. still going sweet.

 

Started at 3.30 to go home (it was bloody hot outside now.) and it was up around 1500RPM

by time i had got a few blocks it hadn't changed. and if it was put into park or neutral would bounce between 1500 & 2000RPM ( i read that this is because it cuts the fuel at 2000).

 

Got to my parents place out of town, and pulled the IACV off, and it was WAY open. More open than it should ever have to move.

 

cant see how it could have opened so much between parking it after lunch and as i started it at 3.30pm.

 

so if you could be bothered reading all that, and have some insight or ideas. im happy to hear them.

 

Im thinking maybe the temp sensor is bung. or its something in the ecu. but hope it isnt.

 

Cheers