Revs up and down on tickover when stopping car
 

Hi, ive been having a problem with my car when it warms up and im driving it and then stop the car, the revs go up and down for about ten seconds then level out back to normal. The car feels like its going to stall but doesnt. Any suggestions please? Thanks.

Sounds like MAF.

Get it checked, it will kill the engine otherwise if it's not right:(

Could also be sticking/dirty idle control valve.

You got any codes showing on the CEL?

There are no codes showing up. The guy who i bought it off just put a new k&n style cone filter on, The original MAF was left on. How do i test the MAF to see if its broken?

Lose the cone filter mate go back to factory air box with panel filter, if they oiled the filter I will have buggered the MAF, and it can't be cleaned with brake cleaner lol

Nice one thanks. Is the STI MAF sensor the same as the WRX for that year because i have a WRX airbox and MAF and could just put that on? Thanks.

As long as the label colours are the same mate so green for green blue for blue so on and so on

Its got a green lable so unless its the wrong one on there i have a spare one. Will give it a go in the morning. By the way, Would brake cleaner kill the MAF if i cleaned it with that?

It should be green label on version 2 Wrx, what year is ur car is it uk or import, and yes brake cleaner will destroy it, cus it's ment to be dry and brake cleaner leaves a residue like some after market filters that need oiling, hence go back to factory with a green cotton panel filter

Ah rite! Its a 95 STI import. Im glad you told me about the brake cleaner cos i get carried away with that stuff lol.

Spray a sh1t load of WD40 down the ICV pipe (disconnect) and then reconnect to the ICV. ;) Done mine recently took a couple of go's but now idles sweet :)

So do you mean spray WD40 into the ICV itself through the pipe or just spray into pipes only?

Well ive sprayed loads of wd40 into pipe and its still the same. Any suggestions please gents?

You could remove it and carefully clean it with break cleaner.

Then remove and replace the MAF with a known working one.

You are sure there are no codes stored?

If those two fail, try taking it to a Scoob specialist, NOT a dealer.

Thanks. Ill try removing the full idle control valve. Will i need a new gasket when i put it back on?

Probably, unless you are uber-careful and luckier than me.

But my money is still on the MAF.

+1

Right guys, i took off the ICV and gave it a good clean out and put it back on and still the same. I removed this then put a different ICV on and still the same soi then went for the MAF as I had a spare green lable MAF and put this on and it threw a check engine light on straight away which means this spare one is knackered, but i cant understand the original MAF isnt giving any code or warning? Any suggestions please?

Yes: get it to someone who knows the cars.
Try Darren at DLM in Darlington.

Cheers. I think its time for the specialist. Thanks.

Mafs don't throw codes unless they do not work at all. A maf that isn't reading right will still be seen by the ECU as working, so hence no code.

Hope this helps,

Graham