Van stalling when revved

[daddyjim]

Hi all,

I have an issue with my 81 2.0L air cooled.
When you start it, it runs on tickover but when you give it a little bit of revs it stalls!
Anyone got any ideas?
Cheers
James

[Bubble Meister]

Timing as a start. Fuel filter. Mixture. Accelerator pump. So to be brief but at work.

[what2do]

What happens if you push the throttle a little bit further? Does it stall or does it go beyond the flat spot and begin to rev?

[SamsBus2012]

^^^whs^^^ - had very similar on mine - with a bit of feathering you could get beyond the flat spot - split diaphragm in vacuum advance unit on the dizzy was my issue - apparently you can get smilar if accelerator pump diaphragm is split (though dont know if you have that on an AC engine).

[Ralf85]

Back to basics. Has somebody turned the tickover adjustment screw down recently? If they have, once the auto choke cuts out then there won't be enough fuel getting through to stop it stalling once it has warmed up.

[what2do]

^^^whs^^^ - had very similar on mine - with a bit of feathering you could get beyond the flat spot - split diaphragm in vacuum advance unit on the dizzy was my issue - apparently you can get smilar if accelerator pump diaphragm is split (though dont know if you have that on an AC engine).

That's what I was wondering. I'm hoping his symptoms will be the same so that I can offer some practical advice for once as this is the only thing my van has suffered from since I've owned it. It's nice to help once in a while........more info required first.

[daddyjim]

Cheers for the help guys, gonna try the tickover screws tomorrow and see if that helps.

[BOXY]

There's only one idle screw if you've got the original Solex carbs. It's on the left hand carb. Setting up these carbs is pretty easy if you follow this. Adjusting the idle is the last thing to do.

http://www.ratwell.com/technical/DualCarbs.html" onclick="window.open(this.href);return false;

[what2do]

Cheers for the help guys, gonna try the tickover screws tomorrow and see if that helps.

You've not answered the above question.

[ajsimmo]

Cheers for the help guys, gonna try the tickover screws tomorrow and see if that helps.

You've not answered the above question.

@what2d - I don't understand your post because:
A) He only posted that yesterday, meaning he's trying the tickover screws today
B) It's not a question

@daddyjim
As said above, technically there's only one "tickover screw", and it almost certainly won't be that. The ratwell guide is very useful, if you have a gas analyser.
First job with twin Solex (for me, anyway) is to balance the air flow with a carb balancer. It's also essential to make sure that you have no air leaks. Common places are the right hand elbow on the rear balance pipe and t-piece to brake servo at other end, idle circuit pipework joining hoses, and vac pipes to dizzy. Also seen these carbs come loose at the base, so check they're tightly bolted to the manifolds.

[what2do]

I just thought that if op was experiencing problems then perhaps he would know what it was like to drive in general and if the flat spot could be overcome by 'pushing through' it so to speak. Perhaps providing more data before making any adjustments. I didn't wish to imply that he immediately go and try to drive the van and report back instantaneously - I'd be willing to let him make a brew first!!

[daddyjim]

I can Rev it as much as I like, it's only when the revs die down that it stalls. It does sound to me like it's miss firing. Think I am gonna have to take it to someone who knows what they are doing as I have no idea and will probably make things a lot worse. Anyone know of a good vw mechanic in the new forest area? Thanks again for all your input peeps.

[Bubble Meister]

You say that it's misfiring - is that when you rev it up, when you drive steadily or on deceleration? Or all of them? Is the pull down unit working? It's the black vacuum unit thing on the carb - it slows the deceleration rate.

[daddyjim]

It sounds like it's miss firing all the time. I will check the other things later tonight. Cheers

[BOXY]

Is the pull down unit working? It's the black vacuum unit thing on the carb - it slows the deceleration rate.

An air-cooled is a twin carb so it hasn't got one of those.