I'm desperate. My 95 wagon.
Full decat exhaust.
Dawes set at 16psi.
Hks filter.
Fuel cut lifter.
Uk 300 intercooler.
New plugs, 4 coils, Knock sensor, cam sensor, crank sensor, maf sensor,boost presure sensor, full earthing kit.
When its hot and you take you foot of the accelerator the revs drop down and it sumtimes stalls (only now and again).
After you stop for a few minutes and then drive off again, when you put your foot down, as soon as the turbo spools up it misfires or chugs along and feels like it wants to blow up. When you run for a few miles it clears up again. It feals like heat soak but even after putting the new intercooler on it hasn't altered.
If anyone wants any more info please call me on 01427 628195 or 07970630132. If anyone can sort my problem out i will refund any phone call money and time.
Thankyou.

 

Have you got the blanking plates for the two front bonnet vents off?

Had a very similar problem when I took mines off, put them back on and all was OK.

I know its a long shot.......

 

Not sure on your model. Is the lamba sensor in the decat downpipe and has that been checked ?

Dave.

 

Lamba sensor is in the decat but not checked. How do i check it.
Got blank plates on.

 

sticking idle speed control valve.

 

Which is the idle speed control valve and how do i clean it.
£10 could be yours....

 

I failed my MOT with a catless exhaust. 2 weeks later the lamba sensor failed with an intermittent (sic) fault. Could be worth trying,

Dave.

 

I have been driving round with a full decat system and bonnet blanking plates off for the last 2 months with no problems!!
Running 16 psi sounds the likley cause...have you increased your fuel cut off point?
Sounds like a fueling problem to me BUT it's a difficult one to diagnose faults without having the car in front off me!!

steve.

 

On MY95 it could well be the fuel cut off point - had MY93 WRX remapped to 15.7psi as any higher you're stepping into fuel cut off territory.

 

But then as you have a fuel cut lifter I could be talking complete tosh!

 

It runs fine when cold, warm or hot, its just after you have parked up and stopped the engine for a few minutes and then set off again that it happens.Its just very hessitant mostly around 4000 to 5000 rpm.

 

So what's it to be? Ok hot or not?

 

Your ISCV is just to the left of your throttle body on the inlet manifold.
I reckon it sounds like an air leak after the turbo, are all your hoses on correctly? i would say that it sounds like the MAF is reading airflow and fuelling accordingly but the engine is not seeing this much air.. Could be a few things...

Rob

 

The revs drop when hot but the misfire is when i restart after being hot.

 

"It feals like heat soak but even after putting the new intercooler on it hasn't altered."

I could be wrong, but unless you have switched to a FMIC - which I don't think you have, your new intercooler will still suffer from heat soak, it will be able to recover better once you are moving again, but it can't do anything while the car is stationary and switched off. So it'll heat up just like any other TMIC and when you re-start and move off it's probably heating your charge air not cooling it.

That doesn't explain the dropping revs though, only the hesitation.


[Edited by AvalancheS8 - 8/25/2003 3:53:06 PM]

 

Sounds to me like the problem is when the engine isn't at running temp but the car thinks it is, or it thinks it's a cold start but isn't. ie temperature probe/thermostat type thing related.
Or quite possibly/probably the lambda - they are very temperature dependant, and start to do most peculair things when they are begninning to go wrong... How's the 'economy' been going recently?
Try an ECU reset & then let the car idle for a while (until operating temperature reached). Disconnect the lambda sensor & see what happens. If idling was appauling before the lambda sensor was disconnected & much better afterwards, this was the problem. If the disconnect made no difference, it's something else... idle stepper sounds likely.

 

Economy is cr*p at the moment but i put that down to me thrashing it when i'm frustrated at the hesitation.
How do i stop heat soak.If i wrap the exhaust in heat wrap (tape) will it help?

 

Try replacing the Coolant Temperature Sensor...it tells the ECU what temperature the engine is at so it may be telling the ECU your engine is cold when it is infact hot and your misfire may well be overfuelling causing the spark plugs to foul up.
Its worth a try....a common fault on Ford Zetec engines that gives a similar fault.

steve.

 

Crap economy also points at dodgy lambda.

 

If the engine was over fueling wouldn't my air/fuel meter say very rich.

 

The AFR gets the reading from the lambda - if the lambda's reading wrong, so will the AFR