Having some idle problems on my P1 - it sits nicely at 750 when settled, no hunting or anything and its boosting fine. But still sometimes when you pull up it drops down to 500 and then back up. Also, when started up when warm it immediately jumps upto 1500 before settling down again? I have tried a brand new maf, which made no difference and tried fitting another lambda sensor. Also tried cleaning the idle control valve, again none of which helpded. It doesn't do it all the time only sometimes when you come to a stop or blip the throttle when stationary?

Please someone help, I don't know what to try next.

 

sounds like your dump valves leaking bud

 

thanks for the info, is there a way to check it / clean it or something?

thanks

 

In my experience, 'cleaning' the idle valve does pretty much nothing. The bit you can get at to clean is only one crucial part out of three that could go wrong. You'd think that if you've got idle problems the very first thing people would look at changing would be the idle valve, not the last. Doesn't help that it's £250 odd from Subaru though. Get one cheap off a scrappy and see if that helps. I had battled with weird idle problems for a year, hearing it was the MAF, a DV leak, a vacuum leak, 'just one of those things', all this bull****. In the end after trying to take the original idle valve apart and realising it's non serviceable, I just got another idle valve and it fixed it FOR GOOD.

 

Also, now when I start my car from cold in the mornings, it will try an idle at 800 or so before realising that it is cold and jumping upto 1300 ish?

And now everytime its started when warm, it will jump upto 1300 ish before settling down to 800 ish?

Could this be the idle control valve then?

 

Mine like this i just put it down to cold weather

 

bttt

 

I have this problem on my v4 STi so I took out my intercooler and exchanged the idle control valve with a secondhand part. I then tightened all the dumpvalve pipes and refitted the intercooler. It still has the problem