Thread: TDV6 High Pressure Fuel Pump

Ean, Is the sensor separate from the pump or somewhere in the line to it? I baulk at chasing repairs with parts. My experience with an outboard motor which I could have replaced for less than what I spent on bits has made me wary of this line of action.

I found this in the manual. Is this the sensor you are referring to?
The fuel pressure sensor is located in the forward end of the common fuel rail for the RH cylinder bank. The sensor is
screwed into a threaded port in the end of the fuel rail.
The fuel pressure sensor is a piezo-resistive type sensor containing an actuating diaphragm. Deflection of the diaphragm
provides a proportional signal (output) voltage to the ECM, dependant on the fuel pressure within the fuel rails.

Originally Posted by orville

Ean, Is the sensor separate from the pump or somewhere in the line to it? I baulk at chasing repairs with parts. My experience with an outboard motor which I could have replaced for less than what I spent on bits has made me wary of this line of action.

I found this in the manual. Is this the sensor you are referring to?
The fuel pressure sensor is located in the forward end of the common fuel rail for the RH cylinder bank. The sensor is
screwed into a threaded port in the end of the fuel rail.
The fuel pressure sensor is a piezo-resistive type sensor containing an actuating diaphragm. Deflection of the diaphragm
provides a proportional signal (output) voltage to the ECM, dependant on the fuel pressure within the fuel rails.

in the end of the passenger side fuel rail is a high pressure fuel sensor according to what I have read , I have ordered 1 of these from the UK . Not sure if that is at all possible to cause the faulting but with it being so random and looks simple to change its worth a try .

cheers Ean

Whilst the car is a daily driver, its mostly freeway 100kmh driving, frequent speed changes and no slow cruising around town. In my opinion, slow cruising seems to be detrimental to these engines.

Did a 500km round trip through the WA south west last Sunday, car was faultless, although it highlighted a minor suspension noise (bushes I suspect)

I just had my D4 serviced in Osborne Park. I discussed the HPFP in the D3 with the mechanic, he looked at it Wednesday with his machine and found the same fault P00087. His opinion was new pump would be about 4 1/2 hours labour plus parts. Do the timing belt at the same time. My opinion is that it is

only verbal and

will work out more than that but still sounds reasonable.

Originally Posted by orville

I just had my D4 serviced in Osborne Park. I discussed the HPFP in the D3 with the mechanic, he looked at it Wednesday with his machine and found the same fault P00087. His opinion was new pump would be about 4 1/2 hours labour plus parts. Do the timing belt at the same time. My opinion is that it is

only verbal and

will work out more than that but still sounds reasonable.

He will mean the rear timing belt that drives the pump as the easiest way to deal with that belt is to cut it in situ. You then remove and reset the self tensioner, install a new belt and unlock the tensioner and boom, you’re off and away (insert removing pump in amongst that.

Originally Posted by Ean Austral

I added some fuel treatment after getting a run of faults each day , sometimes 2 times a day , since adding the treatment and giving the car a couple of good bursts of the loud pedal , and a few runs in command shift where I would let it rev more than normal it seems to have settled down again and hasn't faulted in over a week.

I'm slowly developing a theory on this. Since mine started faulting frequently last week, I've had plenty of opportunity to "play" with the fault.

It looks/feels very much like the pressure control valve is "sticking". It's a solenoid actuated piston that pushes on a ball to balance against the fuel pressure and it very much feels like as the valve is closed *slowly* it sticks. Sometimes it stays stuck and you get the fault, and sometimes it pops loose and you can feel it suddenly develop more power as the fuel pressure jumps.

Driving it "vigorously" results in the valve closing in a more assertive manner and this seems to not allow it to stick. When tootling around a slight increase in requested torque results in the ECU calling for "a bit" more pressure. It tries to close the valve up a bit, sees no increase in the rail pressure and (in my car) repeats this until the valve is commanded ~55% closed. It holds it there for 2 seconds and then signals a fault. When getting into the loud pedal, the ECU figures out it needs a lot more pressure quickly and closes the valve a lot faster. It doesn't seem to stick when you do this.

Is there anyone in Perth who has a duff EU4 pump (destined for the shredder) I could trade for a suitably expensive beverage so I can strip it down and get a better understanding of this mechanism?

Sounds like a good theory but can it be fixed or avoided without the expensive pump replacement?

Originally Posted by orville

Sounds like a good theory but can it be fixed or avoided without the expensive pump replacement?

Thus my interest in getting an old pump to tear down.