Another problem. (Juddering at speed)

've been having a problem with my 1.1C over the last couple of days.
I'll be going along in 4th gear at 60-70 mph and suddenly the car will start juddering. Naturally I ease off the gas and the juddering stops, then I put my foot down again and 30 seconds or so later the juddering will happen again (again at 60-70mph.)
Earlier I did a longish journey on a dual carriageway and the juddering got worse to the point it wouldnt let me go about 50mph without juddering. Luckily I got to the end of the dual carriageway and back onto normal roads with a 40mph limit and all seemed well.

This has really been confusing me as I am unsure what it could be. It has brand new spark plugs, newish dizzy cap, rotor arm and points (only 350 miles old) and the points gap is correct. I have a weber 34ICH carb which has also only seen 350 miles of action (it was unused when I got it.) The car revs freely and whatever the problem is appears to be speed related rather than related to the revs.

I dont think its carb icing as it happened again today when it was 20 degrees C outside. So im guessing its a fuel problem that must be somewhere else along the line. The only other thing I thought of would be the "rust in the tank" syndrome that mk1's get. Could this be the issue?

Thanks.

Strange one, is it the car or steering wheel that's juddering? It it always at the same speed? Do you ever go past the juddering. I ask as it could be something as simple as a lost wheel balance weight, the wheels might benefit from being balanced.

Only you will know, I might be wrong.

Tian :dontknow:

Its the whole car, almost like it is 'kangarooing'. If i put my foot down whilst its juddering then nothing happens, i have to let off of the gas and wait for it to stop and then put my foot down again.

check the fuel filter as mine did the exact same thing

theres a vacuum advance on the dizzie, follow the pipe that goes from the dizzie back upto the carb. this may sound pre-hestoric undo the same pipe from the carb, if you can suck on it and it aint restricting flow (should stop and you will hear it) get a new un from gsf/euro car parts etc, they aint dear (tenner) and make a difference. them fuel pumps are bobbins n all on small block so worth a try if above dont work,
good luck,
paul

hey

i had exactly the same problem and it turned out to be busted fuel pump! it slowly got worse and then undrivable! a new one was 50 quid and then ran sweet as a nut!

James

From the symptoms you describe could well be rust/muck/water in the fuel system. This could either be from a hole in your fuel filler neck letting in muck/water or rust in the tank from the filler neck or tank itself. Often these bits clog the end of the fuel tank up in the tank or even get stuck in the fuel lines or filter and can cause running problems above 50mph or when loading the throttle when climbing a hill at speed. Check the condition of the fuel filler neck (often rusts on top where it attaches to the inside of the rear arch) and system for rust/holes and fuel filter for muck.

Cheers