Got a new one for everyone here.

Around a week ago, our company delivery van cut out whilst driving and refused to restart. Having a look under the bonnet the first thing I did was swap out relay T10 for a new relay and try again, nothing! Listening for the prime pump, it is feint compared to normal, but there!

Next step, disconnected the feed into the fuel filter and turned her over, there appears to be fuel being supplied but I have no equipment to check the pressure, disconnected the supply INTO the HP fuel pump and again there appears to be a supply here but pressure unknown!

ECU Memory interrogated and found to have a low fuel pressure latch and MAF Flow latch, but nothing else. MAF would not inhibit starting, but low pressure would?

Can anyone advise any possible starting points for next lot of diagnosis?

low pressure will stop it starting when was fuel filter changed last?

I have no idea, certainly not in the previous 12 months and it has been run out of diesel 3 or 4 times? :idea:

Update for this one. We have fuel pressure all the way up until the line from the HP Pump to the rail, but then nothing entering the pots, so my thoughts next are either the fuel pressure sensor on the rail, or something common to all injectors, but all 4 having an issue at the same time is highly unlikely!!

Anyone have anything obvious that I have missed?

Filter checked btw, no obvious signs of contamination, so refitted.

Starting pressure is set from map in the ecu not the rail sensor so having nothing coming out of the hp pump means the regulator, wiring, ecu, don't start throwing parts at it. If you don't have diagnostics and test equipment call a diesel specialist.

Hey Mood, my last post was a little misleading. I have disconnected the feed into the rail and cranked the engine, and seen that we have good flow. I have not done a leak off on the injectors yet, so my reasoning is that with good flow (pressure unknown) out of the HP pump, the sensor is the next step. I know someone who has the same Bosch sensor from a working van that I can slave in and test, this could be cheaper and quicker than a diesel specialist. We really need this van back on the road, but no one is moving around here until Tuesday, and by that time we will have run up another £112 in hire van costs to do the work of the poorly ducato!

***update***

Well, it seems my last post was incorrect! Having done a new collector test on the main supply to the rail, I seem to get a dribble in a 10 second turn over - not nearly as much as I would expect.

Changed the rail pressure sensor any how, just to count that out of the equation.

Performed a leak off test of the injectors, to try and establish exactly what is going on at the business end - and to my amazment, not a single drop out of any of the injectors - which as we all know is not right!!

Started to delve a little deeper now, removed the low pressure return from the HP Pump back to the filter, turned her over for 5-10 seconds and got around half a wine bottles worth - this seems to me to be an awful lot to be allowed to return to the tank at this stage??

So to sum up - we ARE getting pressure from the lift pump supplying the HP Pump, we are getting NO pressure at the point of entry into the common rail. We are getting NO return flow (leak) at the injectors in any form. We ARE getting a high amount of fuel returned to the tank from the HP Pump

My thoughts - HP Pump at fault - what part of the HP Pump remains unclear - although I do know that the third piston deactivation solenoid is working as it should be, as I have had this off and checked its operation against the voltage supplied.

REALLY stuck on this one now guys! New HP pump fitted today, but still nothing! Tested to see what pressure/flow is being delivered and its ZERO!

I could really use some input/inspiration from anyone! My next culprit would be whatever item supplies signal voltage to the pressure regulator, as it seems to instantly be in low pressure setting therefore sending everything back to the pump!

Hi Chris

Thanks for your reply, crank sensor was changed around a month ago due to cutting out, came up on scanner as knackered so swapped it out!

As for anti theft, could be, it's very strange how the pump is dumping everything back to return in the LP system, as though the injectors do not exist!

We REALLY need this van back on the road tomorrow night, feeling the pressure now (or lack of it!):bang:

Hi Chris

There is a cam shaft sensor yes, very easy to get to on the top of the engine - I have taken it off and cleaned it, then refitted it - this is a likely culprit - I have just tested all of the signal voltages in the engine bay, and all are as they should be!

I have 8v going to the pressure regulator, 0v going to the third piston deactivator, 12v going into the submerged pump

ARRRRGGGHHHH

The emanual says that ignition is inhibited below 100bar, so it could possibly be the fuel filter causing a drop in the delivery side to the pump, or as you say the cam shaft sensor - I hope that the correct voltage coming form the ECU signals that it is not at fault - but who knows with these things!!!

***EDIT: I used to be an aircraft mechanic for 15 years (airframe and engine) and these are LESS complicated than this bloody engine!***