Trying to decide what to change 1st, and hopefully one of the wise sages here who understand the diesel fuel and injection system better than I , could comment.

Engine will start 1st time in the morning, whether or not glowplugs are required according to temperature. It idles just fine.
I start and drive off within 10 secs or so. Within 30 - 60 secs of driving (slowly along a rutted track) to will occasional 'miss' or stall altogether. Restarts fine , and no further issues throughout the day.
However, today managed to get to a paved road before the 'mis' and so immediately depressed the accelerator and this time the loss of power was prolonged ( couple of seconds at most) before it recovered.
This only occurs after an overnight stand and about 1 in 5 mornings.
No signs of fuel leakage.
No error codes

Thinking: The filter - pump - injector connections were last dismantled 3000 miles ago (pre emptive camshaft swap). Could there be some fuel drain back on the feed side because of air leakage via poorly fitting O ring. This 'bubble' is pulled through and bled back after the LP pump return but causes a blip in the supply pressure to HP pump and loss of pressure for injection. By calling for increased fuel injection at the time of the initial 'mis' the whole bubble is now destined for the HP side and causes the prolonged loss of power?

Is my thinking of the LP / HP pump sequence correct?
Any other thoughts? I discounted crankshaft and camshaft sensors as the problem only occurs in these specific circumstances.

Before go replacing O rings ( Fuel filter due for a change soon) , I do plan to let it idle for 5 mins before setting off to this if that makes a difference.

Many Thanks

Andy

Hello AndyP, Well first off I would look for damaged cables under the air box just behind the nearside headlight unit, my car had a similar issue but with mine it failed to re start. This was some years ago and the dealer although under extended warranty replaced the damaged cabling. You have to remove either the headlight unit or air box to check.

After the check, if no damaged cables I would fit a purflux ie main dealer fuel filter, a little more expensive than euro cp but the reassurance of a genuine part and warranty too.

Also comes to mind check the battery and all connections for security, failing all this try a full diagnosis from a franchise tester.

Regards

Davyboy.

Thanks .. I remember checking the cabling when you posted originally ... fortunately my loom has the wrapped protection and in fine shape.

Cheers

Andy

I had a similar issue with mine and it was air getting into the fuel line running from the filter to the HP pump. Get someone to lightly press the accelerator and then jiggle the connection coming off the fuel filter with the temperature sensor on it you and may see an air bubble run through the line followed by a misfire, well I did anyway when I had the problem.

Hi Luke,
It was your original post that got me contemplating air leakage.
Trying to perhaps over analyse, rather than taking your 'waggle it' approach.
So far, letting it fast idle for a couple of minutes before accelerating hard seems to avoid the issue , so I currently on your line of thought.

All this 'fly by wire' just makes things more complicated. Can't even rev the engine under while under the bonnet .. Perhaps someone has made a remote throttle attachment for the Canbus port?

Luke G wrote:

I had a similar issue with mine and it was air getting into the fuel line running from the filter to the HP pump. Get someone to lightly press the accelerator and then jiggle the connection coming off the fuel filter with the temperature sensor on it you and may see an air bubble run through the line followed by a misfire, well I did anyway when I had the problem.

It would be great if someone has measured the O rings ....
Otherwise a job for me to publish later.

AndyP wrote:

Otherwise a job for me to publish later.