Juddering at high speed

[Lukeh17]

Driving back from the UK to Germany, the two hour trip to Dover and the journey from Calais - Belgian/Dutch border was fine, however, the car suddenly started juddering a couple of times, like almost skipping a beat, then it stopped and carried on. Later on, once in Germany, it got to the point where it was losing power and I had to stop. When I lowered the speed, it didn't seem as bad but as soon as I reached 50+ it would do it. When I finally thought enough is enough I could hear a knocking sound from the front, not 100% sure where and even the back there was a similar noise too.

The car would always start fine after and no warning lights came on. Once I stopped the engine and restarted, it would be back within 20 minutes. In the end, I was on the back of a recovery truck with 120km to go!!

Any ideas what it could be or has anyone else experienced this problem?

[mark1gls]

What car you got?
Carb or fuel injection?

[Lukeh17]

Carb, 1.6 EW engine

[mark1gls]

Webber or pierburg?

Things I would look at, rubber carb flange for split and air leak.
Blocked fuel pick up, blow down the fuel lines to clear and blockage.
Rotor arm, dissy cap, HT leads and spark plugs.

[Lukeh17]

It is a weber carb. It was weird how it did it at only high speeds and was intermittent

[unknownmale]

Sounds like not enough fuel or too much air.

I'd suspect vacuum leak Like Mark said, carb flange...I've replaced two in the last year due to splits.

Worth replacing the inline fuel filter before the fuel pump, cut the old one open and hope for no rust flakes!

[Lukeh17]

Thanks unknownmale

[G-Dub]

Had exactly the same symptoms coincidently driving in Germany. Took VW a couple of days to source the fault and it turned out to be a partially blocked lift pump filter mesh inside the tank. Has been alright for the last 20+ years!