Hi, went for an hours run today in the B and had an intermittent engine judder at all speeds (70mph & 30mph). Rev's don't increase or decrease on the rev counter, coolant level is fine - do you think its muck in the fuel lines and I need to change the fuel filter? Its just been in to DTR who cleaned my fuel lines and replaced the clips in order to cure the cabin cockpit smell, but that was a couple of weeks and a few hundred miles ago.
Any ideas / suggestions would be appreciated. I'm thinking fuel filter, air filter, redex injector cleaner........

Put some Wynn's Formula Gold Petrol Treatment in the tank today - will check the air filter tomorrow...

New air filter, cleaned the throttle cable - any ideas?

You're sure it's the engine? And when you say intermittent, how frequently do you feel it?

Its a very quick lack of power -rather like a 'surge' like but in reverse.
It can be when I'm accelerating or just normal driving - it can happen at 2.5k revs, 3k or just over, and its really intermittent - (not kangaroo at all) can be minutes apart but in a 10 minute drive it'll be up to 10 times on average (roughly) - its not all the time, but I cant think what it is.
I'm wondering whether its anything to do with the variator that I had replaced, but I've had a couple of good hour and a half runs after that without this problem, so maybe not.....

Doesn't sound like a variator problem. Sounds more like fuel supply. Are you getting any noise from the fuel pump? Listen for it at the offside rear. They get noisy when they're on the way out.

Thanks - will do. Is that where the fuel filter is too?

This sounds exactly like the problem I had years ago with my Alfa 33. Electronic cleaning of the fuel injectors sorted it. It came back though, as there was crud in the tank. After several cleanings, it kept coming back, so I had a new tank and the problem went away. Might be worth looking into?

Thanks Ginestra - I think you're right. The weather hasn't been good enough to use up a tank of petrol but after a quarter has gone, with the injector cleaner in, it seems to happen a bit less frequently.
Thanks for the heads up though.

Bottles of injector cleaner weren't enough - I wasted loads on them. I needed to have the injectors out and cleaned ultrasonically. It wasn't cheap, but it really worked.

Hi, where did you have your injectors ultrasonic'd if there is such a word? Is this a specialist or any 'old garage' thing? Thanks Ginestra.

Hi, it was a good few years ago at an Alfa specialist in Gloucestershire. He was really good, but he retired. When he did, he sent me in the direction of Mech repairs in Cheltenham. They've done some work for me in the past and I was happy. I think they do untrasonicking! They also have a good rolling road :devil:. Not too far from Oxfordshire either.

Ginestra - everyone says its expensive - what's 'expensive', can you remember?

Hi j33,

I recall £80 as the figure, but that was over ten years ago. That included labour. It'd probably be a lot more now, but it worked for me after trying lots of other ideas without success.