any ideas re CU engine issue..

[katykoo]

I had a new petrol tank fitted the other week, and took the van for a 200 mule trip, on the way home it hit a few moments on the motorway when the van held back momentarily.

It ran fine for a few days, and then started to do the same thing again. Then on Saturday, driving to pick up new spark plugs, it backfired. I had new plugs in, and today it stalled a few times on decceleration. I have checked filters, hoses, air filters,aand all seem's to be ok. A while back my mechanic said that the distributer was rusty and would need replacing, and I hadn't got round to changing it. Could this be at fault?


It starts up straight away after stalling and has no issues starting up either.
The cap and leads are around 12mths- 18mths old.


Its an electronic ignition set up, and I want to know which distributer I need to get? That's if this is suspected at fault. Its a CU 2 litre with twin weber's.

Thanks

[kevtherev]

backfire on the overrun, stalling, hesitation, means you could have a small airleak on the inlet side.
gaskets, vacuum hose connections etc

[katykoo]

Thanks, I had checked all the hoses yesterday, and couldn't see any signs of splitting or deterioration. Where is the air inlet? Also, which gaskets are you referring too?

Thanks

[kevtherev]

Any thing that goes from the head to the airfilter is on the inlet side

so anything on that side that lets air in (other than the filter) is not helping

any gaskets that have spilt will be shown up by spraying them with carb cleaner

[Plasticman]

As kev says, im also not of the school that suggests replacing £££parts untill the fault is found, perhaps if the fitter and i use that word, stood the cost of any parts that turned out to be ok we may have a more educated assessment
mm

[sarran1955]

Hello,

Lots of photos please...

Cordialement,

[katykoo]

hi all, thanks for the answers.double checked all hoses for signs of spilitting, they were all new around 18ths ago, none found. I haven't yet checked the carb gaskets. The exhaust is also 12 ths old. I'll try and upload photos', though I am currently unwell! so ay not get photo's for a bit. kept the revs up yesterday en route to work, and all was fine. Journey home it stalled several times, refused to re start and backfired. Got it going again, and we cruised home! The van often gets a bit jerky when it needs a service, so will get cap and leads changed, and ights as well order gaskets for the carbs?

[BOXY]

Check the electrical connections to the idle cut-off solenoids on the carbs. A couple of weeks ago a spade connection came off on my right carb and every time I took my foot off the throttle coming up to a junction the engine stalled.

Ah, just noticed you've got Webers not Solex's. Not sure if Webers have got cut-off connections?

[katykoo]

seeing as I need to get a new dizzy, what type do I need, and where can I get one from? Thanks

[kevtherev]

Wait
A distributor merely directs the spark to the cylinder at the right time
If it's doing this... You don't need one.
Take a plug connect it to the lead,any lead, lay it on the engine.. Then look to see if it sparks
If it doesnt spark
Let us know and we'll go from there

[katykoo]

well, backfiring sorted thanks to a service..still getting occasional hesitation, I haven't anaged to check for air leaks, except all hoses are definitely ok.I have ordered carb gaskets, and hope to get them fitted soon, and hope that by process of elimination this gets sorted.

[katykoo]

Finally got the van into the garage. It was a snapped manifold gasket, the rubber type that sits between the carb anifold and head!! just got to order some!!

[kevtherev]

How was that discovered?

[katykoo]

the garage did air leak test, and then took off carbs, and all the carb gaskets appeared ok, and then they showed me the thick spacer gasket had split in half! I can't locate any where that stocks these! any ideas?
Thanks

[kevtherev]

any gaskets that have spilt will be shown up by spraying them with carb cleaner

That's something you could have done.
Becsuse it's probably what they did

As for the gasket
Have you tried VW Heritage?