Black Mamba

Hello everyone. I hope someone can help.
I own a MY97 UK Subaru Impreza which is suffering from terrible idling problems. It almost stalls sometimes. The problem is of intermittent nature, causing the "Check Engine" light to illuminate from time to time. When this is lit the car does not boost well at all (I believe this is "limp home" mode). I have conducted the diagnostic test by plugging the black male/females together and it tells me fault 24. I believe this to be the idle air control solenoid. I have tried swapping the top part of this solenoid with my mate's Scoob (WRX 94) but the same symptoms persist. I'm thinking that it could be the actual actuator part inside the inlet manifold. Is there any way that this part can be fixed/cleaned? Should I just go out and purchase a new one? I am trying to make sure that this valve is the fault before buying new cos it's an expensive item at £212!
Many thanks people,
Black Mamba.

Mike Tuckwood

Both the symptoms and the DTC have confirmed that it is indeed the ICS. Buy a new one and replace or try a breakers (but you could be ending up with what you already have)?

Mike.

Stuart Taylor

There has been posts on here about spraying carburettor cleaner into the pipe that goes into the valve. There is a 3/4in metal pipe that runs along the top of the engine just infront of the intercooler. On the right hand side it goes into a rubber pipe which then goes into the idle control valve.
Have the car idling and then increase the revs to 1500-2000. Then pull off then end of the large rubber pipe that goes into the valve and squirt carburettor cleaner in. Make sure you dont let the engine revs drop too much as it will stall. Give it several goes and then put the pipe back on and see if it has improved. It can be a bit fiddly trying to keep the revs up and remove and spray but it can be done on your own.
Also it can be done when the engine is switched off but I tried this and found it difficult to start. It did fire up eventually but I think it had to clear out all the cleaner first.

Try this first as it may be alot cheaper than a new valve.

Stuart

Black Mamba

Many thanks both you guys for your advice. I have tried squirting carb cleaner into the valve as suggested Stuart. The car was then tested and it does appear better. I'm not sure if it has cured it though or if it is just me being paranoid about the revs. To test I have been driving the car at about 4000 revs and then putting it in neutral to see where the revs settle. The revs seem to die to about 300 and then creep up to 700. Is this normal for a Scooby? Should I just be bothered about the revs at tickover? I will monitor things to see how the car runs and let you know if it is cured. If it starts to misbehave at tickover again could the valve be removed and stripped down for inspection to save on buying new?

Many thanks people,
Black Mamba

ozzy

Have you access to a Select Monitor or Deltadash software?

I have an idling problem on my MY99 RB5. I was told that the symptoms might indicate a faulty MAF, but with John Banks help we saw that it was the Lambda (O2) sensor that was acting-up.

My car boosts well, but will "hunt" on idle between 500 and 1000rpm. It's never stalled and it's only showed the CEL once - 32 oxygen sensor. With hindsight, I should have realised, but the car drove fine and didn't start getting idling problems until 4 weeks after the CEL appeared.

I'd try to get your car onto a select monitor or find out if someone with Deltadash can help you out.

Stefan

StevieB

Not sure it’s of any help but my UK MY98 idles at dead on 600rpm when warmed up.

Steve

Black Mamba

Thanks again.
I am considering putting my car onto the Select Monitor to see what it comes up with. It is my belief that it will check out all the sensors for me once and for all. Am I right in saying that the black plug DIY self diagnostic check will only highlight the last fault? If this is the case there could be more than one sensor fault and I wouldn't know. Hence my consideration for the Select Monitor. Once the problem is cured will I need to do an ECU reset?

Thanks,
Black Mamba.

ozzy

AFAIK, yes it will only show the last fault code.

If you plug-in Deltadash it would list all the codes since the last time the ECU was reset.

On a MY99, the MOT idle speed should be 750-1050rpm. When you look at the O2 sensor using Deltadash, you see a nice wave when the cars idling. At the moment mine looks like some 3yr old with a crayon in their hand

Have a look here http://www.scoobynet.co.uk/bbs/threa...d=90011&Page=2 for some of the graphs from Deltadash - it's great (I'm in no way connected with EcuTek, just love the product)

Stefan

Black Mamba

Many thanks.
I took my car to the Subaru dealer who plugged it in to the Select Monitor only to confirm fault 24-the ICS valve. He sprayed some carb cleaner in as I had tried earlier but I am still having the same problems. My question is can this valve be removed and analysed properly (stripped down) and repaired? Has anybody done this? Also I would like to check the wiring as the Subaru dealer told me that there was a possibility of a wiring fault. Has anybody got any info on wiring checks for this particular fault? It is driving me mad this fault as the car is running awful!
Cheers,
Black Mamba.

ozzy

Sorry m8, but I haven't a Scooby if it can be repaired

Stefan