Got round to trying the 'IV drip' tonight.

Firstly, I disconnected the filter to HP pump hose at the filter. I then added a separate piece of hose to the filter into a bucket and turned on the ignition - good spurt of fuel for the 3ish seconds the LP pump was doing it's thing. Doesn't appear to be a problem on that side of things.

I then connected the HP pump hose up to my clean supply if diesel and turned the car on. It started for about a second and then died. And then wouldn't start again. The bucket by this point was getting pretty full!

This looks like an HP pump problem doesn't it?

What I had failed to mention before is that when it was starting, I then had to wait 5/6 minutes before getting it to start again.

What I'm thinking now is that the HP pump was being completely emptied of fuel when the car was running. It then wouldn't start again for 5/6 minutes until it slowly filled up with fuel. Then it would start and die again.

Does this definitely sound like an HP pump problem?

Or could it still be something else?!

Sounds like the lp is eliminated.I wouldn't condemn the hp pump yet . Next on the list for me would be a careful check of the crank sensor and wiring to the ecu. There are a few other cheaper options to check. It could be the fuel pressure sensor or regulator on the rail or wiring from the ecu to the injectors. A fuel leak back could pinpoint a leaky injector but generally it's only one and the car is just hard to start and a bit rough.
As Ziggy said earlier the pressure in these things can cut flesh so be careful.

The low pressure pump is designed to supply more fuel than the high pressure pump needs. So sounds, as I suspected that the low pump was fine.

My money is still very much on the high pressure pump this is far more likely, mechanically, to fail then a fuel pressure regulator or injectors.

One injector could leak or fail this wouldn't cause the engine to die it might cause a misfire bore wash or lots of black smoke but not the other 3 cylinders to pack up as well. And I think it very unlikely to be a fuel rail fault.

The high pressure pump produces very high pressures at the injector, high pressure low volume so take the tiny injector nozzle out of the equation and the high pressure pump isn't able to produce the scary pressures that are spoken about above (still be careful mind)

If I were you I'd look for another pump especially given the age of the car, symptoms and their propensity to fail

Hasn't stopped raining today so no chance to get under the bonnet.

Used the fiatecuscan software though it test some actuators. Specifically the fuel pressure regulator which completed it's test - does this mean the regulator itself is ok?

Does FiatEcuScan give you an output for the actual fuel rail pressure? If so then what is it?

My money is on, like Andy, the high pressure pump seals failing.

could this not be an air lock in the fuel supply?

if you open the pipes at the injectors slightly, just enough for them to leak when you crank the engine over. do you get fuel coming out of each one?

try them one by one

when you replaced the fuel filter di you check it or the fuel in the filter housing? the reason i ask is when hp pumps tend to fail internally they break up and the filings go through the fuel return system back to the tank ,they inturn get pulled back through the fuel system and trapped in the filter housing, also have you cheked the rail pressure sensor ( do not remove unless you released the immense pressure in the fuel rail first if in doubt DO NOT REMOVE ) as again i have known these clog up with filings from a high pressure pump breaking up


AGAIN IF YOU ARE UNFAMILIAR WITH HIGH PRESSURE DEISEL SYTEMS DO NOT ATTEMPT TO REPAIR AS IT IS HIGHLY DANGEROUS

Any news on progress?

the bit circled in red is the stop solenoid

Apologies for no recent update - haven't had a chance at all to look at the high pressure side yet.

However, I did want to go over everything I've checked before so started with electrics. Crank sensor is new so just checked it was installed properly - looks fine. Checked earth connections - they all look ok. Then I looked at the fusebox and checked all fuses individually - all of these were fine in the fuse tray.

However, there is a 60A fuse just to the left of the tray running alongside it. This has blown. What is this fuse as it's not included in the diagram underneath the fuse box cover? I'm assuming (hoping) this could be my issue?!!

garysmith21 said:

However, there is a 60A fuse just to the left of the tray running alongside it. This has blown. What is this fuse as it's not included in the diagram underneath the fuse box cover? I'm assuming (hoping) this could be my issue?!!

Click to expand...

I believe its for the Electric Power steering, do you have a power steering warning light when you get it to start and run (albeit briefly)

Found out what it was in the manual - part of the glow plug circuit. Replaced it and it hasn't made any difference.

So I can't find anything electrical.

Moved onto LP side again. Does the pump in the tank run for a set amount of time? Mine is running about 8/9 seconds every time and sounds quite weak. Although it's getting fuel to the filter and onto the HP pump to allow the car to start, could it be causing the car to die if it's not then pumping enough up to the HP side of things once the car has started?

garysmith21 said:

Moved onto LP side again.

Click to expand...

:bang::bang::bang:

scoop987 said:

Does FiatEcuScan give you an output for the actual fuel rail pressure? If so then what is it?

My money is on, like Andy, the high pressure pump seals failing.

Click to expand...

It does give me a reading - between 300 and 400 bar when starting. It pretty much matches the desired fuel pressure reading.

I can then rev the car once its started and again the actual pressure matches the desired pressure.

Then after a good few seconds the pressure falls and the car dies.

If your getting 300-400 bar, and filter clean of any metal filing, it can't be the HPP.

So outwith the HPP, can the ECU, for some reason, be shutting of the fuel with the fuel cut-off solenoid? Other than that, it can be the crank or cam sensor or wiring (I think it has been mentioned before though?)

Does the ecuscan give an output for fuel pressure on the lp side? Nine seconds seems awful long. Any diesel I'm used to has the priming thing sorted long before the glowplugs switch off.

scoop987 - that's why in the back of my mind I thought it might not be the HPP so double checked the electrics and the LP side. The crank sensor is a brand new bosch sensor and I followed the guide on here for installation ensuring the old 0-ring came out etc. I still need to double check that it is sending a signal to the ECU.

Brendan - not that I can see. I guess I could manually measure how much fuel goes through the filter in that 9 seconds. How much would normally go through in 3 seconds? I'm pretty certain it didn't used to take that long.

I keep going back to the fact that this started after filling a near empty tank. If it now looks like the lp pump is struggling a bit I would be thinking about pulling the pump out for a visual and clean out. Can't find anywhere the normal runtime of the lp pump , maybe a friendly dealer service type would tell you.
If it comes to it I know a good Vet

Sounds like a plan. Ruling out everything that is cheaper than the HP pump is good with me!

Managed to try a different lp pump and it made no difference.

So this still points to the hp pump. I just want to make sure though - as the engine sometimes starts and the pressure readings are as they should be, could this still be a faulty pump? Would a faulty pump still give normal pressure readings for a few seconds before it dies?