CraigW

Hi I've got a 1993/1994 K reg WRX, When I fist turn the key it idles at 1500rpm for a couple of minutes then slowly works down to 1000rpm, after I've been out in the car it idles at 500rpm ? any ideas whats wrong, should I be worried ?? or is they anything I can do to get her idling right

KEVWRX95

Craig
The 1500rpm is totally normal as you are in the cold/startup map in your ECU, then after warming up slowly the revs drop to 1000rpm, then once totally warm they should sit at around 800 to 900 rpm, I would say 500 is a bit low,
But you can alter the 500 by turning the air idle valve a couple of mm.
Hope this helps
Kev

CraigW

so it hasnt an air leak or anything ? just i though 500rpm seems low.
If i turn it up, doesnt that mean when it start up it will be on something like 1800rpm ?

KEVWRX95

Craig
No it shouldn't make any difference as mentioned before your ECU and air idle control valve control the cold revs.Just make sure when you alter from 500 upto 800 you do it when the engine is at its warmest !!!!!!!!!
You may benefit from taking the air idle valve off and giving it a clean, then reset it.

Can I just check, your MAF and plugs/coilpacks are all in a good state aswell?

Kev

CraigW

no idea mate, ive only had the car over a week.
i was going to get the oil and plugs changed but ive been told its a total nightmare to change plugs ?

Moley

iTrader: (9)

KEXWRX95 - to increase the revs should the idle control valve me moved clockwise or anti-clockwise.

I took mine off a while ago and now when i stop the idle drops to 500rpm for a second then goes back up to 900rpm.

KEVWRX95

Moley,
I can't remember, but as soon as you move it a little you will hear the engine note change, so it will be obvious.
If your revs hunt around Moley I wouldn't necessarily think its only the revs/air idle valve, have you got a MAF and how healthy is it?
Kev

Moley

iTrader: (9)

Have never checked anything to do with the MAF to be honest

MadDogWRX

Had a similar problem with mine, also had poor starting (hot & cold).

Found a hair line crack in one of my coilpacks. Changed that and all is well again.

Moley

iTrader: (9)

I do have a mis-fire aswell when i first start to accelerate, so will check the coils.

KEVWRX95

I agree, if you have a misfire when going on boost then check plugs and coilpacks first, then see what you are idling at, your hunting may well be a bad connection between your plugs and coils.

If after replacing the above then check your MAF sensor on your air filter, if they are dirty they will misread the airflow and you will get a hunting effect with your revs up and down, take it off and a very little squirt of brake cleaner on the sensor being VERY careful, let it dry for an hour and put it back together.

Then play with the air idle valve !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Kev.

Sc0oby

can the iac valve be move??????

Sc0oby

anyone??

coleyswrx

it cant be adjusted its just a plate inside a housing that controls your idle if you take it apart you will see what i mean but to take it apart you need to take off the water pipes each side then undo the 4 bolts and slowly unstick the gasket once u do that clean with some carb spray, put it all back together and reset the ecu, it might not want to start for a few turns but it will so dont panic, then it will be fine after that.

Sc0oby

have the same problem except on my v3 model. have change almost evrything including map but still cant solve the problem. Only part have not change is the o2 sensor

ZEN Performance

Just so you know, the mark halfway between 0rpm and 1000rpm is 750rpm.

Sc0oby

hmmmm...any more infor would be appreciated

ZEN Performance

what more is there to know? If you're looking at the tacho and thinking it's idling at 500rpm, the chances are it's idling at 750rpm, which is normal.