Engine Stalls! Electrical Problem?

[Mark V]

Hi All,
Poor GTi's got issues...
(2L 8V Digifant injection system, Engine 2E)

If I'm comming up to a stop, and take my foot off the clutch and throttle, the revs drop so low that either the engine stalls or it manages to just recover and return to idling at normal rpm.
First thought - Idle stabilizer valve!

Well, I pulled the hoses off and just left the connector in. Turned on the ignition and i can see the little valve opening, but only half way... So yes, I'm thinking that the valve is faulty.
But i check anyway by connecting the valve directly to the battery. This time the valve opens beautifully! all the way!

So I get the multimeter out and check the voltage at the connector of the valve, it's 12V... normal. I then plug in the valve again and check the volts. Now they're right down at 4 or 5 Volts...

Should the voltage drop to that under load on that connector? Can anyone shed light on this? Are there any other possible causes of this problem besides the valve?

It idles fine, but even if it's idling and I just blip the throttle up to say, 2000rpm, then release, the revs drop to below normal idle.

help help help help 

Many Thanks
Mark V

[monkeyalan]

dirty throtle body.

get some cleaner and spray it up the air intake, also try cleaning out the butterfly in the actual throttle body.

 

[Mark V]

I'll have a go at it tomoz. thanks. Which cleaner do you suggest?

Any other suggestions?

Many Thanks
Mark V

[monkeyalan]

any carb cleaner mate, doesn't really matter.

good luck

[Mark V]

Hi there,

Tried the carb cleaner, cleaning the throttle body, etc.  No affect at all.

I did however find that when I start the card cold, like this morning, and it idles at about 1050rpm when it's cold, it doesn't have the problem. I can rev up to 3000, then just take my foot off the throttle and it safely returns to 1050.
Bt as soon as it's warmer and the idle drops to 800-900, it gets the problem.
And also when i do a warm start.

What else can it be? What's different when the engine is cold?

[Mark V]

bump

[Greg]

can you check to see if you have a short on the wire which is delivering 4v ?
have you checked your relays and fuses?

[Mark V]

Had a good look for shorts, can't see any. The engine harness, after the multiplug, is a bit dodgy. So I'm gonna get a second hand one just to replace it.

Haven't checked fuses and relays. I assume no fuses are blown as everything works, so which relays must I check, and what to look for?

[Mark V]

Can the Digifant system be diagnostically read? Can I use one of those diagnostic cables you can buy off Ebay?

[smeg760]

Hi mark any luck .
Just put a 2e in my car works spot on when its cold , warms up gets lumpy on tick over and the revs drop below 1000 and it wants to and does stall, read up on hear and thought the cam belt might be out a tooth but why would it be ok when cold ?
will have to check the hc i suppose it does smell a bit.
bumperty bump.
james...