Occasional Juddering On Acceleration
Over the winter, the Spider (Phase 1 TS) was parked on the drive for a few weeks, with abut a quarter of a tank of fuel.
When the tank reached about an eighth full, it started spluttering whenever I accelerated. Thinking it might be a fuel issue, I filled up, and ran a bit through, and it seemed to improve for a while, but still did it occasionally. It's fine when driving at constant speed, and only happens on acceleration.
I took it to a garage, and they replaced the lambda sensor.
However, it's still doing it from time to time. Most of the time, the engine management light doesn't come on, but it did a few times over the weekend. I took it back to the garage, and they cleaned the plugs, saying it could just be some muck, but this seems to have made little difference.
Is it possible that I've got some muck in the fuel filter, or should I be worried that it's something more serious?
Any advice would be greatly appreciated, since I'm a bit fed up of the hourly rate at the garage when they don't seem to make much difference to it.