Thank you once again! Slowly eliminating so potentially getting closer.
I didn't catch the part about it being PWM rather than binary on the solenoid, but I eliminated my initial thought to make sure the ECU wasn't killing/cutting the fuel at the valve. I guess it could be setting this wrongly, but as you say you'd need to take the rail pressure to know for sure.

Reading the rail pressure would be the absolute best, but unfortunately can't do that with my test gear. I know I'm being cheap but for other reasons I'll not go into I'm at bare bones cash so doing as much as I can before admitting defeat!

I've also checked the wiring loom and harness and all looks good, did connector 'waggle', etc. including from BCM and fuse tray connectors. Sounds odd but it doesn't feel like an electrical glitch.

Without testing rail pressure I'm stabbing in the dark but I wonder about the injectors now, if I've got one or more acting up and under load/higher RPM they're leaking too much. It's another guess unfortunately.

 

Check the wire harness right where it goes under battery tray to the trany. You need to cut the black isolation up to see if there is a broken wire inside"this is cheep" .

Next you meter/prop valve on HP pump could be stuck or the rail sensor could be bad . They work together , sensor feedback to ECM and ECM give signal to Prop.valve.

Moste likely a broken wire seen this many times and offen when engine get hot the isolation get soft and wire connection get bad due to vibration . When cold if offen works again.

 

You could change the valve or the rail sensor , it's grabbing in the dark to solve . I know the wire's is a little had to get but with front wheels on a block/ramp or on a lift you can access them from below. You might need to remove the left wheel inner plastic fender to get access some of the harness goes from trany moduel and it's placed in the left fender below the headlight. and join with the wires from fuesbox . Offen it in this lumb of wires there is a broken wire.

When you follow the wire there is a bump on the isolation (this is where is failure is ) and it's course by the copper is corroded if you pull the wire on both side of the bump it will brake and you can solder it together again.

If common on cars today that wires go bad with out reason , I'm guessing it's poor quality copper or isolation . It's not only a Chrysler problem !

 

Found many failures this way , Headlight , ABS , Airbag , Start problems , com problems between BCM and ECM ,TCM .

 

Thanks for the further replies.

I'm positive it's not electrical as the cutting out is very specifically engine RPM related, not vibration, etc. this is more mechanical, so back to looking into the fuel feed.

However, the problem has now stopped! The only action I've taken is to unspin, remove, inspect and re-insert the fuel filter at the rear by the tank. I've not replaced the filter, but perhaps this action has re-seated the rubber o-ring and this has had an impact?

Other than that, and putting in decent diesel with an additive (redex injector cleaner) things are working great again. Very unusual!

I'm continuing to monitor it and will post back if anything changes, but for now I'm back in the running!

 

Good to hear

I all ways lube the new o-ring when change the filter , it can be a real pain loosen again if not and it also help not ruin the seal when tighten the filter . make sure the aluminium is clean where the o-ring is suppose to seal.

I notis many of the filter's in marked got a poor quality o-ring "kinde of hard material" so it's even more difficult to get seal right. This is also a problem with new oil filters . Old days it was made of real rubber"NBR style material"

 

A small magnet into the diesel filter housing is also a good idea , like in the transmision .

All this dry running/air in system will cause dammage to the HP pump and injector over time and small metal fragments will return to tank .

Modern diesel fuel dos not lubricate very well so every time you start the HP pump / injector will get hurt by the air in system . "I assume this is why 2.8 got all this problems compare to the 2.5 "

I know you got the lift pump but the car didn't have the pump from factory this way . There is a reason it got this ad on kit mounted.

 

I recently replaced the HP Fuel Pump Filter and Housing and this seems to have solved my cutout problem. The car also starts much better. The diaphragm inside the fuel filter housing was distorted and looks likely to have been the culprit.

 

Good to hear you solve it , manny don't belive this but it's a fact seen this problem manny times .

 

Thanks, yes, it's a strange one as there are so many potential faults, something as mundane as a fuel filter housing seems unlikely especially as the fault is intermittent and always under load when it occurred, never on idle.

I took the car for a good run yesterday, autoroute and all and it performed perfectly so I think I can now finally pronounce it cured.