K reg intermittent fault help please

[tig190]

Hi all it's been a while.
I've just had my mk 4 in for it's mot passed with no advisorys
But on the way back it's developed a fault where it's drives fine then won't rev just ticks over turn it off start it up its fine again then after a few miles does it again. The only thing that has been done to it is a new cold start fitted that seems to be when the trouble started.
Diesel must be getting through for it to tick over but I can't understand why it won't rev even pulling it manually timing belt is only a year old and it all locks up in line with the pins.
Any advise would be great thanks in advance

[Chug]

Is this the Bosch VE pump?

And its not revving up when throttle lever pulled by hand?

But switch off engine and restart and its fine?

[tig190]

Not sure about pump I'll have a look in morning but yes that's what it's doing it'll be fine for a while then just no revs it's driving me mad haha

[tig190]

I forgot to say it's a 190 2.5 di 80ps engine

[Noctule]

How is the tickover when it happens? Lumpy or smooth?

[Noctule]

And when was the fuel filter last changed?

[cherniy_chack]

This behavior of the motor is typical for the EPIC system, but not for the BOSH system.

[tig190]

Sorry for the late reply I've been away
The tickover is smooth and the fuel filter is new it's also had a new fuel pump on the block and a new cold start but that's when it seems to have started when ford put the cold start on but they're not having none of it as usual haha.
I'll check the fuel system on Saturday to see which one it is