Worlasshasansti

Hi folks, some may have seen my other posts about my 03 STI idle problem.

Long story sort of short

Car developed an erratic idle and put management light on, used a snap on obd2 reader but couldn't retrieve codes, so changed coolant temp sensor to no avail then changed MAF also no difference.

Car still has erratic idle but only once warm and usually after it has seen boost, so pulled intercooler off and had a good check of all pipes/vac lines but all seemed fine, also tried the carb cleaner technique but again couldn't find anything.

EML came back on when it was sat at idle so read codes again and got the p0507 code relating to IACV system, cleaned idle control valve out with guide on here using drill but still no different.

Bit the bullit and took it to a well respected subaru specialist, car was data logged but data showed everything seemed to be within tolerance ( apart from lambda but it was only running rich when the car was idling funny at about 2k rpm ) plugs were changed as mine were filthy and a compression test was carried out which also came back fine.

My next course of action was to try another IACV but after speaking to a couple of mechanics today we came to the conclusion that surely if the idle control valve was at fault it would idle funny all the time and not only once it warm or been on boost?

I can get an IACV for £35 which is cheap but the fact that I've now spent about £200 and I'm no further forward is starting to grate on me a little now lol.

Anyone got any ideas before I buy the idle valve??

Sorry for the long read

Cheers

Mick

tubbytommy

iTrader: (20)

so you took it to a Subaru specialist but they couldn't tell you what was wrong with it so you're carrying on guessing?

Worlasshasansti

Well I was advised to "try" the idle control valve next but with no solid diagnosis that's about the jist of it aye....

I was just wondering if people thought the valve could only be dodgy after using the car as it idles fine until its driven a few mile?

Mick

tubbytommy

iTrader: (20)

id take it to a specialist that knows what they are doing, if you don't know the problem, buying parts that you may not need can prove expensive.

take it to a specialist, get them to fix the problem, pay the bill job done.

Worlasshasansti

I'm not for a second saying the specialist didn't know what they were doing, the way I'm looking at it is if the ecu isn't logging a problem and the live data is all within tolerance how would any specialist know what's going on, I do all my own work as much as possible so I'm not going to pay a specialist 3 hours labour to remove check various things in the bay when I can do that myself.

Was just hoping someone who may have experienced similar may have been able to give me a clue.

Cheers

Mick

tubbytommy

iTrader: (20)

I had an icv fail on my blob sti and it idled funny hot or cold, revved to 1500 rpm and dropped continuously.
so I doubt its that too, check for air leaks

hpoolsteve

iTrader: (4)

Revolution are in your neck of the woods. They should be able to help mate.

Like tubbs has said mate. It's pointless guessing and replacing parts and chasing your tail.

marshall332bhp

Mick it happened once when I owned it. Took it to A.S he said was moisture between the connectors as he stripped it put it back together and was fine was about 9 month before you bought it.

Worlasshasansti

Cheers chris, its already been over to alyns I'll give him a bell and see if he remembers lol.

I think I'm gonna strip the inlet mani off tomorrow after work and double check everything before doing owt else

Cheers

Mick

Worlasshasansti

Well before stripping the car to check hoses/pipes again, I took the car for a quick blast, but when I returned it was running rough as f*ck idling all over the shop, coughing and spluttering on and the EML came back on so....... Back on the reader and it was coming up with idle valve system and rear o2 sensor.

Spoke to Alyn again, he though the O2 code may have been a red herring due to the idle valve getting worse, bought an idle valve off Matty on here and its right as rain now, thank **** for that I've been out in it today and I'm warming to it again lol.

Cheers

Mick