Thread: New Territory engine in D3, Engine System Fault, please help

Ok, update:

Have tried to bleed the HP end, very little diesel wells out of the fitting. Have tested that there is power on crank to the solenoid on the HP pump. Have checked fuses, relays, etc., all seem good. Have also tested the fuel temperature sensor, the resistance drops as it is heated up, so it seems to be working.

This leads me back to an earlier question: Should I have diesel fall out of the bottom of the filter, from the water drain port? Bear in mind it's an 09 model, so is the short cassette style filter, not the large tube style. When I pull the water drain out, and turn the key to position 2 (lights on) there is no diesel present at the drain. I would have thought that the system should be at least partly pressurised, to lift the diesel to the HP pump. And therefore that when I introduce a depressurising "leak" by removing the drain, that diesel should be forced out of the drain...? This does not occur. I plan to get a few feet of pipe tomorrow and unplug the fuel pipe into the HPFP, plug hose onto the pipe, and feed it into a drum. Should the LPFP continue to pump if there is no pressure? I basically want to pump a couple of litres through it if I can...

Thanks for your ongoing assistance, we will get this damned thing running eventually...

Fuel should flow from the filter drain at least for a while when the ignition is first switched on.

Have you jumpered the LPFP relay to force the pump to run (bridge the large terminals)? If you can't identify the relay (engine panel R8 (micro) on a D4) then provide power directly to the pump's fuse.

Originally Posted by Graeme

Fuel should flow from the filter drain at least for a while when the ignition is first switched on.

Have you jumpered the LPFP relay to force the pump to run (bridge the large terminals)? If you can't identify the relay (engine panel R8 (micro) on a D4) then provide power directly to the pump's fuse.

Thanks Graeme. I have checked the fuse and the relay, both are fine; the relay clicks when turning the ignition on, also swapped it with another realy with the same markings from in the fuse box. I've posted the same question regarding the filter drain on disco3 forum in the UK, and am told that the diesel is held in the filter by vacuum, so doesn't drain out. This doesn't make "sense" to me however, as why would you put a drain on the bottom then hold the fluid so that it can't drain. I'm thinking that the pump is not working properly. I'm off to buy 3m of tube to put on the end of the feed pipe just before the schrader valve, and see if the pump can push fuel.

I would not expect fuel to drain with the ignition off if the HPFP solenoid releases pressure when off. However with the ignition on the pump has to run to prime the system to present pressure to the HPFP so fuel should flow from the drain or bleed valve if open.

I agree that the pump appears not to be operating, hopefully caused by a broken wire, poor connector contact or poor earth rather than a failed pump. If the fuel was too low then the relay wouldn't operate.

Edit: The D4 diesel fuel pump has 2 earth connections, with the 2nd one in place of a fuel pump module used by the petrol engines. If one of those earths is missing then the pump wont run but I don't know if your D3 is the same.

Another edit: Your D3 only has 1 earth for the fuel pump. The fuel gauge operating is not indicative of the pump having earth.

Thanks again Graeme. Approx 65 litres in the tank (but no drain plug, that'll be fun). I got under the car and pulled the drain plug, turned ignition to ON, heard pump "noise" but not a drop from the filter drain. Yeah hopefully it's something stupidly easy, like a dodgy wire or earth. I'm convinced that the whole issue is going to be something simple...

No kinked lines between the tank and filter housing?

My thoughts too.I wonder if a fuel line is kinked or got crushed whilst swaping the mojos.
Andrew

OK, have just gone and plugged a 5m length of 8mm clear hose on the LP pipe that goes into the schrader valve, then run it into a new diesel plastic can. Cycled the ignition 5 times, and it feels like about 1.5 litres of diesel was pumped into the can. The LP pump is on a timer, about 20 seconds each time I think. Diesel was clean and free of bubbles. I can only assume therefore that the LP pump is working at least somewhat, and that diesel is passing through the filter, as I can't imagine that there is over a litre in the lines.

The saga continues...