Chugga, Chugga

[Makebeleaf]

96 Golf TD 1.9

While driving at speed 80-100km, if I let off on the accelerator a bit, the cars starts to chug/hesitate. When I am accelerating it seems to be fine.
Could it be the fuel filter or air getting into the line? I notice sometimes when the car idles there are bubbles passing through the lines and the engine shudders a bit as the bigger bubbles pass into pump.

It has been pretty cold here the last little while... -10-20 with wind. Could that have an effect on it?

[burn_your_money]

Are you leaving it in gear while letting off the accelerator?

I'd check the cam/crank timing just to make sure it's not the crank gear

[Makebeleaf]

Yes, it is in gear when letting off on the accelerator.

I did a timing belt change about 5000km ago/2 months and everything has been good until the last little while.

[Makebeleaf]

Changed the fuel filter (finally!) and it seems to have fixed the problem....I am not getting the air bubbles going to the pump like before and it is not doing the chug chug. Now just fix the leaky turbo and replace the smokey flex hose!...cough cough