GeeDee

iTrader: (2)

I have a MY99 WRX which has a minor problem with throttle response. Put simply, I can not get the engine to freely rev (clutch disengaged) between 900 and 1400 revs.

Not normally a problem unless you are sitting in v slow moving traffic when the throttle is effectively acting as an on/off switch. It gets a touch jerky.

My guess was the throttle potentiometer but I am advised that there are no problems with it.

Is it a mapping problem with the ECU?

Any other ideas? It would be nice to sort it.

Graham

GeeDee

iTrader: (2)

Whyyyyyyyyyyyy doesn't anyone ever reply to my posts?????

Just a simple "Well my car works" would do just to confirm that I am at least visible.

Pleeeeeeeeeeeeeeease reply.

Graham

AndyMc

Good morning gdavey.You are indeed visible

This is probably no help but I thought I would reply anyway.
My my98 is a bit jerky in slow traffic but it feels more like a combination of sharp clutch/throttle and loose engine mounts than anything to do with the ECU.
Around tick-over the throttle is fairly sensitive so its easy to rev up to much when you drive off.
Does this sound like your car?.

Also does it tick over OK? as a bad tick-over may point to the idle control valve thingy

Has it suddenly got worse or has it always been like that?

Have you compared it with another Scoob?

Andy

DJB

The jerkiness that you describe, I think, is due a fuel saving system built into the ECU map. This means that in slow trafic, if you release the accelerator, the fuel cuts completely and the engines jerks. I don't think that its a fault but it is annoying, I agree.

D.

[This message has been edited by DJB (edited 28 February 2001).]

[This message has been edited by DJB (edited 28 February 2001).]

Charlie H

All the old 1.9 Peugeots did this but a lot worse. Basically, as you release the throttle the ecu cuts off the fuel and only starts it again when the engine drops to idling speed. I find that most fuel injected performance cars tend to do this to some degree (some more than others, just ask any pug GTI owner about "kangarooing" in traffic. Their fuel cuts off at 3,000 rpm and only comes back on at about 500 rpm.)
The ecotec air device made a lot of difference on my pug but I've not got one fitted yet to the scoob so can't comment. Re-chipping may also help cure this as the ecu can be told when to cut off. (Pug superchip changed it from 3,000 to 1,200 rpm)

Probably just have to live with it (they obviously don't like going slow)

Of course this is only my opinion and I wait to be corrected

Jim Dunleavy

My UK spec MY99 does exactly the same in slow traffic, very easy to proceed in a series of jerks, it's done it since new, the price you pay for all the HP let loose when you finally get away.

[This message has been edited by Jim Dunleavy (edited 28 February 2001).]

GeeDee

iTrader: (2)

Relieved to hear I am visible.... Thanks.

I do not believe this is a fuel saving "feature". Whilst sitting stationary and not intending to go anywhere, with foot on throttle only, it is impossble to get engine to rev between 900 and 1400 either going up or down no matter how gently you touch the pedal. When you get to around 900 revs, the engine seems to lurch and revs rise by around 1000 settling back at around 1400. For those with jerky cars, try it out.

Tick over is fine at around 700.

Nothing to do with clutch or engine mounts - happens when stationary.

Have not compared it to another scoob.

Nothing to do with power delivery either as rest of range completely smooth.

Has always been there since having the car at 1 year old and 10k miles. Now 22 months old and 31k miles.

Only a problem in slow moving traffic when momentum of car does not override the power. Like when I was stuck on M1 2 weeks ago averaging 1mph over 3.5 miles!

Graham