Gen 4 3sgte idle problems

[kyle mills-brown]

Hi all I’ve done a gen 4 3sgte swap in my 1996 mr2 and it has some trouble it doesn’t idle at all when it cold and when it’s up to temp it idles very low and runs rich at idle would it have anything to do with the stud that broke off in the pic? Thanks all

[Benckj]

That’s simply the stop for holding TB butterfly open a tad. Doesn’t sound like your problem. Are you running the gen4 ECU, TPS and IACV?

[GDII]

I might have to check the wiring for power to the IACV. Or at least you could do the check as I can't come see you. I didn't touch the other 2 wires, just the one to get power to the valve for the ECU to ground either way.

Power should be from pin 2 which is black with red to the centre pin on the idle valve.

Screenshot_20200423-142723.png (378.55 KiB) Viewed 4394 times

[*84vvt]

The IACV may possibly need a good clean.

[kyle mills-brown]

Great thanks for the tips guys I’ll check up on all that and hopefully it’ll work

[kyle mills-brown]

Thanks so much guys I checked the wires and they had power to I pulled the IACV out and cleaned it now its nice and shinny now the car idles perfectly when cold and then drops down a bit once it’s up to temp as it should

[Benckj]

Good work. The IACV seems to be a common fault with 3sgte’s and not many owners ever look at until it fails.

[GDII]

Glad you got it sorted. Always frustrating to have a car that won't idle properly. These valves are never cleaned so quite often stick.

[GDII]

Good work. The IACV seems to be a common fault with 3sgte’s and not many owners ever look at until it fails.

It's a 3SGE and 4AGE thing too. I think it's a general 90s Toyota problem now that they are getting older and filled up now with enough stuff to stick them in place.