idle problems

[COS25T]

my car is running a 1jzgte with r154 gearbox. i have been having problems since i had an electrical drain fixed. when it is cold it idles low and when it warms up it idles around 1200. sometimes after i turn it off and back on again it wants to sit on 4000. it goes down again after i turn it off and on a few times. before this started my normal idle was 600 and went even lower if the air con was on. any help would be much appriaciated.

[naten]

check you ISCV (idle speed control valve) its on the back of your plenum, take it off clean it and make sure its working. Easiest way to tell is to listen for it clicking when the ignition is turned off.

If that doesnt change it maybe its faulty or something is up with your tps?

Only things that can really effect idle are iscv, tps and throttle plate opening. Assuming there isnt a air leak somewhere.

[COS25T]

i checked the iscv. there is no clicking noise. i read in another thread how to test it so i took it off. it makes a click noise but the valve doesn't open or shut.i can get a new one for 80 bucks. does this sound reasonable?

[COS25T]

sorry i take that back. it is working. it moves ever so slowly. it moved from open to shut. i put it back in and now it idles low at about 500 when cold and 850 when warm. im guessing that the problem could be the computer.

[naten]

850 when warm sounds almost right?

ifs its idling too low when cold maybe its the cold start injection? or wiring?

Could be a million different things but id probably be taking it back to the place that found the electrical drain and tell them to fix it, thats assuming they caused it

[COS25T]

it seems fine when warm so i think i might leave it for now and get it looked at after christmas. thanks naten for the help.