Page 1 of 1

Occasional Juddering at high speed cruising

Posted: 25 Apr 2008, 21:22
by nesty
Hi

I just returned from a trip to Norfolk, the camper did real well. However only snagg, when I cruise long distance for long periods at around 65-75mph. I suddenly start get a juddering, like back and forth like kangeroo juice. It never does it urban driving, only comes on sometimes when doing high speed cruising say after 2/3 hours of driving.

I find I have to reduce speed a lot down to 40 mph or in some case pull over, but then it's fine.

One time a couple of months ago I went up to Leeds on M1 there and back and it didn't do it at all. However this week did it twice there and back to Norfolk.

Any ideas what it is I am thinking of putting it in a for a service anyway. Though just wondered what it could be?

Nesty

Posted: 25 Apr 2008, 21:28
by syncrosimon
If this is a 2.1 DJ, then it's normalish, what engine is it.

Posted: 25 Apr 2008, 22:14
by nesty
A 1.9 water cooled Waserboxer.

Posted: 25 Apr 2008, 22:16
by R0B
i must have an abnormalish one then....

If this is a 2.1 DJ, then it's normalish

Posted: 25 Apr 2008, 22:49
by syncrosimon
Sounds to me like your fuel pump is only just keeping up with demand, that could be the anomaly. Otherwise ignition, and weak spark, which will be worse under load.

Posted: 26 Apr 2008, 11:42
by nesty
Ok thanks for this. I might put it in for a service anyway to get it ironed out.

It only does it occasionally, but I can tell when it kinda gonna do it. If I take my foot of the gas and go to put it back down, it take a second or so to get going again and get a slight jolt.

I know some modern cars have a valve that shuts off the fuel when you don't have you foot on the pedal then opens again when you put your foot back down. Seems a bit like after lengthy crusing something isn't letting the fuel straigh back through.

Nesty

Posted: 26 Apr 2008, 15:41
by ermie571
clogged fuel filter....
:?:
Em
x

Posted: 26 Apr 2008, 16:51
by syncrosimon
Could also be the vacuum units that operate the secondary throttle. The rubber perishes and can cause eratic running. There is I believe a test procedure in Haynes for testing. Troubleshooting is difficult, but as the carb is shared with other VW models of the era eg Golf and Scirocco's a general VW specialist may be able to work out the problem.

Posted: 27 Apr 2008, 09:11
by Aidan
i'd go with worn fuel pump pushrod and dirty filter or multiple filters

Re: Occasional Juddering at high speed cruising

Posted: 26 Mar 2009, 15:12
by Mrben88
Did you ever get this sorted, I've still got the same problem!

Thanks

Ben

Re: Occasional Juddering at high speed cruising

Posted: 26 Mar 2009, 17:35
by nesty
Apprently mine has the wrong carb & manifold on it (a 1.6 one). The garage have recomended a change, as it could be the floats drying up under vast flow on motoway driving.

I don't do much motorway driving, so when can afford the change will do it.