Engine cut out [stall] off auto choke

[Nathanb]

Hi All - As the subject line says my van is now cutting out as soon as it comes off of autochoke.

As it's my first van and I'm not that experienced at messing around with the fuel system, I therefore have it booked in at a local garage that was recommended to me by another VW T25 owner; I'm hoping that they can help fix it but before it goes into the garage on Monday morning I thought I'd throw this out onto the boards to see some opinions on what people think could be causing this issue, or at least get some ideas for investigation that I can then pass onto the garage.

So here's some information of my van and what's been happening:
VW T25 [Water Cooled] Autohomes 1991 Petrol 1.9
Pierburg carburettor

Bought the van in June this year. Ran fine until September when it first cut out on me but this was when idle at traffic lights. re-started the engine and then carried on as usual.
This intermittent issue started to then happen a little more regularly, each time it would have an issue when on idle, so I would need to keep the revs up and drop clutch to change gear. But then often after doing this for a bit it would then be fine and tick over as per usual on idle.
I had a friend give it a good service, changed spark plugs, oil, oil filter, air filter, petrol filter on petrol line from tank to engine bay. He had it cut out on him once but then after service it ran fine for about another month.
About 4 weeks ago it cut out again after driving around for a bit, took it back home on high revs, then next day when I restarted the van it ticks over on the auto choke but as soon as I kick the acceleration down for it to come off of autochoke it then cuts out.

So i've tried to read up as much as possible and so far from what I can gather it would be any of the following, let me know if anyone else has any ideas??????
1) Carburettor jets etc. blocked - possible refurb needed.
2) Autochoke issue
3) Air leak in hoses
4) Air leak in Carburettor gaskets

Thanks
Nathan

[ajsimmo]

Dirt in carb blocking jet or bad connection on idle cut-off solenoid.

[bigherb]

Any times when it is particularly prone to do it? Very cold? slow moving traffic?

[Santa79]

I'm having the same problem with mine as of today.
It started happening as I was bleeding the coolant system. I've had the top off the carb and cleaned it with spray carb cleaner, but it's still happening

[kevtherev]

My 10p
The idle jet is very small and the only way to clean it properly is to use a stiff bristle.
The bodge method is to rev it up hard and put your hand over the venturi, the huge vacuum sometimes shifts any offending crap from the idle jet.
Assuming the choke is fully open after about 6-8 mins, then another reason could be an air leak into the induction side.
My money would be on the anti dieseling valve (idle speed cut off) due to it's intermittent behaviour in answer to the OP

[ajsimmo]

What I said outdide a nutshell ^

[kevtherev]

What I said outdide a nutshell ^

indeed my friend.. boredom compelled me to expand

[Nathanb]

Thanks for all of the feedback Kevtherev & Ajsimmo! Gives me a good list to discuss with the garage on Monday.

Ideally I would try to strip down the carb and clean it myself but I just don't have the mechanical confidence at this point to give it a try.

To answer 'Big herbs' question of "any times when it is particularly prone to do it? Very cold? Slow moving traffic?"
When the intermittent cutting out started to happen, it was always after the engine was warm but apart from that no other consistent behaviour. But now it will cut out as soon as it comes off of choke.

@Santa79 - I hope that you have some joy with getting your problem resolved, I'll keep this thread posted with what fixes mine.

[ghost123uk]

bad connection on idle cut-off solenoid.

My money would be on the anti Dieseling valve (idle speed cut off) due to it's intermittent behaviour

+ one on that

Also note that whilst not impossible, it is very rare for blockages to cause intermittent problems.

I wouldn't be going splitting the carb to check for muck before checking that fuel cut off solenoid and any other factors outside of the carb first. Also, if you are going to split the carb I take it you will have a new gasket to hand?

[NicBeeee]

The only time we have had to concede and call the big orange van was due to a similar fault to yourself, intermitent stalling issue after the autochoke had come off, also seemed to worsen when driving uphill. Stuck in the middle of no where the man in the orange van gave the float chamber a blast from above and off we went, "slightly embarrased but happy none the less", when home I split the carb to find quite a few crystals had formed in the float chamber and were swilling about, cleaned the carb out and has been fine since. You can clean out the float chamber from above by blasting air into the mesh covered hole top left of carb, do it with a cool engine and be careful to cover your eyes and face as fuel will undoubtely spray out but hold a rag over the top of the carb and this should catch the worse, (health and safety covered)

[Nathanb]

Dropped my van in on Monday for its MOT and also this problem with cut out on idle. They said emissions were fine and only one issue with a faulty light, so got that sorted.

First report back on the idle issue was that they did a vacuum test on both the
choke pull-down diaphragm and secondary throttle diaphragm and said that the levels were low, so would need replacing. Advised me that it might be worth changing the whole carb to a weber.

So wanted to get opinions on whether this would be a good idea or not?

[ghost123uk]

If you use the search box on here for weber, you will find that most folk find they do not work well on the WBX engine. Much cheaper and better to get the excellent Pierburgh carb sorted. All the parts are easily available. There are a few places that will refurb it to a high standard for less than a Weber anyway (or you could DIY it).

[kevtherev]

refurbish it!
Bromyard VW

Weber..

[ajsimmo]

NOooo...... Don't touch a Weber with a long one.
Thankfully the Weber carb kit as a replacement for the Pierburg has been discontinued and is NLA. Happy days!
Another vote from me for Bromyard VW refurb service.

[Nathanb]

Thanks for all of the responses, looks like it's a resounding NO for a weber conversion and a big thumbs up to having Bromyard VW refurb service.

So the good news is that the garage after further investigation has also found sediment in the bottom of the carb once they took it apart. They have also confirmed that it's near on impossible to obtain a Weber conversion and instead have agreed with everyone's comments on here, to send it off for a refurb. So looks like there's a 4 to 5 week turnaround before we get it back, get it fitted and tuned on a rolling road.

I'll keep the thread updated once i get some news as personally I've found it always handy to read the final outcome to other peoples problems on here.