Pierburg carb problem

Post by **fairwynds** » 30 Aug 2007, 16:41

Hi all
wonder whether anyone can help with this one?
A friend in my street also has a van like mine, although has a slightly later DG engined 1900 water cooled. I have taken the following details from the side of the carb: 2E and the figures 025129 015H VW/AU 9 040

He has an intermittent (carb?) problem, which he describes as follows:-

".........the fault on the van has been occurring for more than one year. It appears to occur randomly, sometimes within a few minutes of starting the engine, sometimes after 30 - 45 minutes of driving and sometimes not at all.

Symptoms:

The engine suddenly stalls. This appears to happen when the revs are low. When braking the engine cuts out.

It is possible to avoid the engine stalling when slowing down, if the brake is used gently and the engine put into a low gear and the accellerator used to keep the revs high. However even then, when the van is going slow enough (the revs are low) it suddenly cuts out.

The engine starts again, once it has stalled, provided the revs are kept high. If the engine is left to idle it stalls again immediatly.

When the engine stalls, it does not cough and splutter and appear to struggle, it just cuts out.

The engine will continue to stall for the rest of the journey.

Sometimes the problem has remedied itself initially when the van is next used.

When the van was usd last Friday, the fault occurred immediatly. The revs had to be kept high, just to start the van........."

In my (albeit limited) carb experience Im thinking choke fault? But could anyone help with other ideas or tests that can be performed to trace the fault please?

Thanks all.....

FW

Post by **toomanytoys** » 30 Aug 2007, 16:59

More than likely that there is some crud floating about in the carb bowl.. (billy "stuck in 88" had similar problems a while back)

Gasket kit is cheap from VW and cheaper from GSF..

But there are lots of things that should be checked also..
All the little pipes on the carb and dizzy, the brake servo vac hose and any electrical conections on the carb..

Crud in the carb usually comes from the filler neck rubber has perished (or worse) the metal filler pipe corroding and letting spray into the tank.. or the tank has rusted out on top.. or the small vent pipes on the tankare perished.. if they look like crud, then the tank should be dropped and it all fixed..
Have a look at the fuel filter near the tank.. if it has a load of crud and water in it.. thats the problem...

Website · Post by **CovKid** » 30 Aug 2007, 18:29

Try getting hold of the throttle flap spindle (base of carb) and see how much up and down movement there is (not side to side). Any air leaks via this shaft will make idling a hit and miss affair - mostly miss. If its worn it'll leak.

Having driven V-dubs (all kinds) for some 30 years, you see a lot of worn throttle flaps. Any good engineeer with a precision lathe can sort this for you - if it is indeed the problem. VW's really HATE air leaks on the inlet side. Basically, once the throttle flap shuts the engine relies on a tiny air feed through the carb block. If theres an air leak anywhere else then it will never idle right. The throttle shaft is a prime candidate. Same applies to bugs although you can also get leaks through the rubber inlet joiners, inlet pipe gaskets - anywhere from the throttle flap and on into the inlet.

Steve at Gasure does them (although only if fitted by him) and theres a guy near me in Coventry that also does them - fits phospor bronze bushes.

Post by **toomanytoys** » 30 Aug 2007, 20:30

Generally the pierburgs dont suffer this trouble that Solexes do... mabe they have a better bush in them already..
By the way, my DG carb has over 300k on it, only ever had a couple of gasket kits...

Post by **kevtherev** » 30 Aug 2007, 20:39

I've had water in the tank/filter/carb do this to me...but a dirty carb/filter sounds like the culprit as toomanytoys suggests

Post by **hembo666** » 30 Aug 2007, 22:41

Well im very interested in this as my van has had the same fault since we bought it and i have so far failed to find an answer.

i do believe it will be carb/choke related when i do sort it though.

Post by **fairwynds** » 31 Aug 2007, 11:16

Thank you all so far.......will be passing on this info. Will keep you posted.

Post by **DentedDevon** » 01 Sep 2007, 18:52

I think the bypass cut off valve can cause problems like this , it closes the passage which the idle mixture passes through .
(stops the engine running on when you switch it off)
When mine went it failed completely , would not tickover at all.
Missing or disconnected preheat hoses can cause similar problems , but usually in cold , damp weather.

Post by **toomanytoys** » 01 Sep 2007, 19:13

Good point DentedDevon.. but normaly running issues can be put down to crud in the fuel system... this is the most common problem

Post by **hembo666** » 05 Sep 2007, 06:47

can someone post a pic of the bypass solonoid so i know where i am looking. cheers

Post by **DentedDevon** » 05 Sep 2007, 20:43

I think this should get you to a picture

http://shop.justkampers.com/product_inf ... s_id/10353