Please someone help!!! (idle)

[A.k.]

My small port ae86 4age won't stop hunting for an idle it just goes between 1.5k and 2.5k, up and down, up and down!!
It's driving me nuts, please help, how do I fix it??

[70XIN]

unplug TPS, see if hunting goes away. if it does, TPS needs adjusting or replacing

also check your coolant level, and try and bleed the system if you can, any air bubbles can make it chuck a hissy fit

[A.k.]

Ok sweet, I'll try bleed it.
Sorry what does TPS stand for??
Did this happen to you aswell?

[70XIN]

Throttle position sensor. It's the black thing with a plug going into it on your throttle body.



^^ That's a TPS

[Nikkojoe]

If the hunting goes away after unplugging, it will probably still idle at 2k. An adjustment wont fix it, you need to lower your idle (adjust idle screw all the way down if need be). If your idle is at its lowest, you will need to see for any post throttle body leaks. This also means checking to see if your cold start idle up valve (one under the throttle body) is working correctly, you may need to remove it and plate it off if you haven't hooked up the cold start coolant lines. Also remember that the ports on that valve must be blocked off individually is not in use, do not loop vac hoses on them to block them off as it creates a bypass.

[A.k.]

Oh ok I have a look after work, if I unplug the TPS and the hunting goes away do I replace the TPS sensor before driving again?

[timbo]

if it was the cold start idler (bit under the throttle as nikkojoe said) it wouldn't hunt it would just rev at 2k all the time, this happened to me.

[A.k.]

Just unplugged the TPS and it stopped hunting, plugged it back in and it started hunting again.
It sits at 3k when TPS is unplugged, do I leave it unplugged, what now?

[17zon]

undo the screws and move it till it stops hunting and revs freely the smallest adjustments make a big difference(you wont break anything playing with it)

[A.k.]

Ok I'll do that tomorrow morning and post how it goes.