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Model specific boards => Golf mk3 => Topic started by: general_piffle on 25 March 2014, 21:10

Title: Weird starting fault when engine warm?
Post by: general_piffle on 25 March 2014, 21:10: Hi, I wondered if anyone had experienced the same thing or knew what this might be?

Say I drive to the shops, do some shopping, then go back to the car and start it up when the engine is still warm it starts but the revs rise and fall rhythmically without me touching the pedals. The only way to stop it is to turn the engine off and on again or sometimes if I give it some revs it settles back to normal.

It feels like a sensor of some description is playing up and feeding the engine false information. It's been going on for about 2 years but has been getting worse recently and will need fixing soon.

Any ideas as to what it might be?! Cheers.
Title: Re: Weird starting fault when engine warm?
Post by: itavaltalainen on 25 March 2014, 23:17: what engine code? mileage? what condition is it in (serviced at all)?
Title: Re: Weird starting fault when engine warm?
Post by: general_piffle on 25 March 2014, 23:51: 16v GTI MK3 from 1994, 69,000 miles, serviced 3,000 miles ago (still had the fault then but not as frequent as now) oil and filter change about 10 miles ago.
Title: Re: Weird starting fault when engine warm?
Post by: VR6_Wherry on 26 March 2014, 09:04: Have you cleaned the throttle body out with carb cleaner?
Title: Re: Weird starting fault when engine warm?
Post by: general_piffle on 26 March 2014, 23:36: Quote from: VR6_Wherry on 26 March 2014, 09:04
Have you cleaned the throttle body out with carb cleaner?

No I haven't and to my knowledge although the car is very low miles for its age this has probably never been done. Could it simply be this? Cheers.
Title: Re: Weird starting fault when engine warm?
Post by: thai-wronghorse on 28 March 2014, 20:49: Potentially, yes. Also worth giving all the breather hoses and idle stabilisation valve a good clean.
Title: Re: Weird starting fault when engine warm?
Post by: general_piffle on 28 March 2014, 21:27: Quote from: thai-wronghorse on 28 March 2014, 20:49
Potentially, yes. Also worth giving all the breather hoses and idle stabilisation valve a good clean.

That sounds promising. Where does the idle stabilisation valve live? Cheers.
Title: Re: Weird starting fault when engine warm?
Post by: thai-wronghorse on 28 March 2014, 22:16: It's the cylindrical unit infront of the intake manifold (with the black plastic ignition lead holder removed)

(http://img.photobucket.com/albums/v260/shaggyjh/Mk1%20Golf/ABF%20Conversion/2011-05-28173446.jpg)
Title: Re: Weird starting fault when engine warm?
Post by: thai-wronghorse on 28 March 2014, 22:18: Beneath this

(https://scontent-b-lhr.xx.fbcdn.net/hphotos-frc1/v/t1.0-9/1922011_10153943383105693_1873467054_n.jpg?oh=bacaab61810efb051e1e29e1c5dc4d7d&oe=539F6A78)
Title: Re: Weird starting fault when engine warm?
Post by: general_piffle on 29 March 2014, 01:56: that's really helpful thai, thanks. I'll get them to have a look at this next service, hopefully it'll be an easy win :)