Car stalls when braking

[motah33]

Hi,

I have a VW Golf GTI 8v 1990/H (engine code PB) with the Digifant Fuel Injection system.

When slowing the car down, the battery light flashes or stays on and the car stalls. I can start the car instantly after this happens - several times on a journey. I try to blip the throttle to prevent it from stalling. When the car is driven at normal speeds there are no problems.

Recently, the car had to have its mixture adjusted in order to have its MOT pass. I don't know if this has had an impact as it seems to have run ok since then.

I took the battery out and put it on the charger and the 'full' light came on straight away. I wasn't expecting this as if I constantly have to re-start the engine when it stalls, I would expect the battery to be fairy depleted especially if the journeys are short i.e. not enough time to re-charge the battery. The voltage across the terminals is 12.97v.

What I find is that the when I blip the throttle, as the revs drop, it feels as if it wants to stall but then recovers i.e. it shoots up and then comes back down again. It is a bit erratic during idling. Sometimes it seems to sort itself out when it has been on the move for a while, say 30 minutes. But most of the time, it is only doing runs which are no more than 10 minutes.

Any help would be much appreciated.

Thanks

[mk2bal]

Blue temp sender and rjs setting up guide probably wouldn't go amiss

[Andy!]

I'd be looking at the idle valve pal, sounds like yours is approaching the fecked point.

[emery1990]

Does it get better when hot, if so then its idle stabilisation valve probably.

[motah33]

Thanks for all the replies. I really appreciate it.

Yes, it does seem to improve when it gets hot. In fact, last night, the problem disappeared after 30 minutes of driving. The problem has only occured so I don't know if this is consistent.

"Blue temp sender and rjs setting up guide probably wouldn't go amiss" - how would this temp sender affect things? And what is "rjs". Thanks.

[cняis]

Thanks for all the replies. I really appreciate it.

Yes, it does seem to improve when it gets hot. In fact, last night, the problem disappeared after 30 minutes of driving. The problem has only occured so I don't know if this is consistent.

"Blue temp sender and rjs setting up guide probably wouldn't go amiss" - how would this temp sender affect things? And what is "rjs". Thanks.

http://www.golfgtiforum.co.uk/index.php?topic=33253.0

[mk2bal]

there is a guide by rj - rubjonny - a member who knows his onions on setting up golfs. I think this guide is in the maintenance section, it will take you through everything, right from the cambelt timing onwards etc. The blue temp sender tells the ecu what temp the engine is, and the ecu adjusts things accordingly. If this sensor is unaccurate then the ecu is giving the wrong settings for the engine which causes poor running if you catch my drift... However yeah it could be the isv,or the cam cover pcv bung thing, it could be many things really, best to go for a search on here and see what you find..

[motah33]

Thanks for all the suggestions/links. I shall go through them and let you know what happens.

[logeyboy]

Heel & toe...

[motah33]

Here's an update:

1. When I switch on the ignition, but don't start the car, I can hear the ISV buzzing.

2. When I open the throttle just a tiny amount I can hear a switch click which I believe is the Idle switch and from what I read this is the correct behaviour.

3. If I blip the throttle and rev the car, the revs come down and the car almost stalls (with the car stationary) but recovers.

4. If I start the engine, let it warm up, then disconnect the blue temperarure sender, it stalls immediately. I can start the car without the sender connected but I have to keep the revs up to stop it from stalling.

5. If I disconnect the ISV (electrical connector), I can start the car but as in the case of the temperature sender, I have to keep the revs up to stop it from stalling.

If this provides any more cluses as to the cause, then please let me know.

Thanks