Car was running ok... then all of a sudden loss of power, but boosting ok.

I thought it was the plugs so I changed them... still doing it. But now the car was over revving and ticking over at 2500-3000rpm.

Turns out it was the coil pack not firing on one, so I've changed the coil pack and the car drives beautifully again, BUT still ticks over at 3000rpm.

There's no air leaks that I can find, all vacuum pipes on the manifold seem fine... I've swapped over the map sensor to try and eliminate that, still doing it.

Any ideas??

 

The 'check engine' light is also on sorry forgot to say.

It all seems to have happened when I changed the plugs, but I didnt disconnect or touch anything else at that time.

I'm a bit stumped

 

Could the fuel pressure regulator (mine is oem) have anything to do with this?

 

Read the fault codes. Possible idle control valve stuck. What year car?

 

I'm gonna go down to a friends garage 2moro morning and I'm hoping his machine can read my fault codes...

Its a '99 STi.


ps: also forgot to say I've got a Simtek so no MAF.

 

Which is the idle control valve is that the switch attached the the throttle body? I tried disconnecting that switch but it made no difference

 

Elo sweet cheeks, ows it going? your car is knackered again lol!! Anyway if you need your fault codes reading i have a diagnostics for most impreza's!!

 

And its free LOL

 

PS I think you have the wrong plugs??? lol

 

Throttle cable too, thats not gone tight/stuck/moved???

 

mines done the same after sitting a few weeks,turns out the stepper motor was sticky on the idle control valve,just a case of removing it and giving it a soak in some wd/40,easy cheep fix.oh and dont remove when engine is hot as its water cooled.

 

I'm gettin the diagnostic done free 2moro morning and he's only in Barnet on the way down to my dads (Igott go do sum work on my bro's car down there).

I got PFR7B's in there, they're not the wrong plugs you slag! lol

 

my car has been off the road 2months... could be the same jobbie?

any pics of the idle control valve? so I dont go removing the wrong thing for a DW40 bath, lol

 

i didnt think that simtek let you read error codes?

 

Nope it wont. Not via obd. Need the simtek sofware.

 

ah **** really?

 

Sounds like icv stuck.

Not sure on classic but on newage make sure you change gasket.

Screw heads will be goosed too. So best bet is get hold of some m5x20mm (i think from memory) hex head screws.

Steve

 

dont be like that alex, your the slag!

 

Yup. Clean the idle valve is the first step. Mine sticks if i leave the car sitting a while. Mines a little different to your so cant help you with location. Should easily find it with a google search

 

I hope its as simple as the idle control valve... just weird how it was fine up til changing the plugs then straight away, blur!

Ok I'll do that first (and look out for hex screws as a give away for its location

And yes Lee, I cant disagree... I am a man-wh0re lol

 

Also my anti-lag used to be mega explosive around 4krpm, but now only pops and bangs around 2-3k?
I cant see how the idle would effect that?

 

your idle control valve is easy to take off and clean you wont need any gaskets just make sure the rubber o ring is ok and goes back in,have you tried spraying carb/brake cleaner on the vacuum pipes and around the manifold? sounds like an air leak could be the gasket on the manifold?

 

yes it will alter it as the icv is used to allow air into the system while the buttefly(throttle) is closed. From what youve just said r.e. Anti lag. Im convinced its the icv at fault. My anti lag behaves the same when mine sticks.

 

I did think it could be an air leak not that easy to spot so was gonna try the brake cleaner trick 2moro

 

Excellent I like a positive diagnosis!

I'm extra keen to get it off and clean that sucker up now!

As long as I figure out where it is exactly, lol

 

Sorted:

http://forums.nasioc.com/forums/showthread.php?t=781242

 

ok if you look at the engine bay at the center of the manifold just above to the right youl see a silver round jobbie with 2 screws take it off and squirt it to death

 

I'll hit it with more brake cleaner than its ever seen!

In a way havin the rev's not dropping below 3000rpm is great when you're racing. You're always on peek rev's for max boost

Will make a mental note if and when I ever do a track day (a worth while map to have for that instance)

 

lol ive just had a problem like yours and it made me not even want to drive it everytime i stopped at the lights it sounded like i was ready to launch,good luck m8

 

Yeah I feel a right tw@t when I pull up at the lights, ppl look over like wtf is wrong with you, are you tryin to egg me on for a race? lol

So did you cure your problem the same way by cleaning the ICV?