VW Golf GTi Mk 3 2.0L - problem with stalling when coasting

[youngsyr]

Mate has an issue with his VW Golf GTi Mk 3 2.0L stalling when coasting in neutral up to junctions.

Holds cold and warm idle fine.

Emissions are fine as per latest MOT, so thinking it's not the O2 sensor.

Has changed air filter with small improvement.

Could it be Idle Stepper Control Valve needing adjusting?

He doesn't have radio PIN code so disconnecting the battery to reset ECU parameters is best avoided.

Can anyone provide any pointers? Thanks.

[martycossie]

clean out throtal body and check the pipe to brever may be be broken

[youngsyr]

Thanks, does anyone else has any ideas?

I think on a lot of modern cars you can adjust the idle by adjusting a screw on the throttle body, can you do this on the VAG models?

[aka_kerrly]

youngsyr said:

Thanks, does anyone else has any ideas?

I think on a lot of modern cars you can adjust the idle by adjusting a screw on the throttle body, can you do this on the VAG models?

yes but this isnt fixing the problem it mearly masks it for another couple of weeks and will make the engine sound like it has air leak.

The problem is most likely as the previous posted described you have a dirty throttle body and most likely a dirty ISV (idle valve - a cylinderical item that buzzes, if it doesnt buzz its dead.)

clean these out with petrol or carb cleaner and then see what happens.

[blueST]

I would go over every vacuum pipes looking for splits too. Air leaks can cause idle problems. Don't forget the brake servo pipe too. If there is a leak you can quite often hear it if you listen carefully immediately after switching he engine off.

[cpas]

I may be able to half help here - I read something about this on Honest John's website - but I can't remember what the diagnosis was!