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rich17865
21st March 2015, 15:03
There is a problem with dad's diesel.

when at 70mph ish, you put your foot down there is juddering.

It has had 4 replacement refurbished injectors, full service including fuel filter.

T4 says everything is acceptable in the fuel system and the maf is just slightly out of spec.

Both in tank and under bonnet pumps are running. Unplug the in tank pump and the under bonnet pump will start the car, the other way round and the car doesn't start.

There is some gurgling from the back of the car in the in tank pump area. But only very occasionally. The in tank pump does seem to have a high pitched noise about it. But disconnecting the fuel lines suggests the in tank pump is pumping, although there is not much pressure.

Any suggestions on how much fuel should be pumped by the in tank pump, is the high pitched noise normal, why the gurgling and more importantly, why the judder under speed when accelerating?

lightningmark
21st March 2015, 16:31
I had similar issues with judder under acceleration and it eventually turned out to be nearside driveshaft. Replacement cured it Rich

rich17865
21st March 2015, 16:50
Thanks. Disconnected dodgy Maf which has helped partly, but the judder is still evident at higher speeds around 65 plus

lightningmark
21st March 2015, 17:11
My judder was only evident under acceleration and only at speeds in excess of 60mph. If I took foot off pedal then judder would disappear. I replaced with a 2nd hand driveshaft

rich17865
21st March 2015, 17:26
That's exactly it, although, I can reproduce the juddering at lower speeds in a high gear. It feels like fuel starvation, but the engine is running smoothly.

Like you say it is much more noticeable above 60mph