Mysterious Fuel pressure Drop L322 04 (Pros only please)
#1
10-01-2013, 08:43 PM
Mysterious Fuel pressure Drop L322 04
Folks
I would like to share a case of study, my fuel pump died slowly most likely due to a clogged filter,first hesitated randomly, Stall 2 times, went back to normal for a while, I monitored the fuel pressure and noticed small pulsations (not normal) after noise from the pump and finally died in my driveway ( very lucky)
The procedure wassimilar that the ones in this forum:
Refused to pay $1,200for the fuel pump assembly at the dealership or $800 at auto parts, I bought aOEM (fuel pump only) Pierburg brand (German but made in Poland) for $300 and aMahle filter OEM too, after the swap and taking care of every step carefully I put the assembly back and the filter, then voila! Running like new!
Also magically all thecodes went away after awhile ( PO171/PO174, etc, etc)
After 2 days, the Rangiedid not start properly, went put the fuel gauge in the fuel rail, pressureperfect (50psi) and steady but after shutdown the pressure drops to 30psi in 30sec and in 2 min reach cero... then problem identified! But not...
Reviewed the ravemanual and the dealership catalog with all the fuel components, and not checkvalve was found, called 4 dealerships in CA, AZ, NY and one in UK and nobody (parts and technicians)have a clue where the check valve is! Unbelievable.
Started the researchand found the BOSCH OEM pump have it inside on the fuel pump (very small)
The tests done:
1) Took the old pumpand applied 50psi from the outlet: bingo! Not leak, then BOSCH is right, thenon-return valve is inside!
2) Disconnected the fuel filter lines (underneath, driver side) I made special fittings, cero leak and applied 45psi through aclear hose full of gas to the fuelfilter outlet (blue hose towards the tank) to test the leak at the pump: surprisenot leak, no gas movement! Then the Pump should be ok!
3) In logical orderthen the problem is a leaky injector, then repeated the procedure and applied45psi to the filter inlet (towards the fuel rail) surprise! Not leaking! And the fuel gauge remains at45psi
Then at this point achecked again the fuel diagram and there is not another elements in thepressure line. Dealership doesn't know.
Potentials
1) Another element notconsidered?
2) Remaining power onthe injectors from the ECU and leaking because are opened?
Your guys think that Iam missing something?
The ideas will be veryappreciated
Thanks Gabo
I would like to share a case of study, my fuel pump died slowly most likely due to a clogged filter,first hesitated randomly, Stall 2 times, went back to normal for a while, I monitored the fuel pressure and noticed small pulsations (not normal) after noise from the pump and finally died in my driveway ( very lucky)
The procedure wassimilar that the ones in this forum:
Refused to pay $1,200for the fuel pump assembly at the dealership or $800 at auto parts, I bought aOEM (fuel pump only) Pierburg brand (German but made in Poland) for $300 and aMahle filter OEM too, after the swap and taking care of every step carefully I put the assembly back and the filter, then voila! Running like new!
Also magically all thecodes went away after awhile ( PO171/PO174, etc, etc)
After 2 days, the Rangiedid not start properly, went put the fuel gauge in the fuel rail, pressureperfect (50psi) and steady but after shutdown the pressure drops to 30psi in 30sec and in 2 min reach cero... then problem identified! But not...
Reviewed the ravemanual and the dealership catalog with all the fuel components, and not checkvalve was found, called 4 dealerships in CA, AZ, NY and one in UK and nobody (parts and technicians)have a clue where the check valve is! Unbelievable.
Started the researchand found the BOSCH OEM pump have it inside on the fuel pump (very small)
The tests done:
1) Took the old pumpand applied 50psi from the outlet: bingo! Not leak, then BOSCH is right, thenon-return valve is inside!
2) Disconnected the fuel filter lines (underneath, driver side) I made special fittings, cero leak and applied 45psi through aclear hose full of gas to the fuelfilter outlet (blue hose towards the tank) to test the leak at the pump: surprisenot leak, no gas movement! Then the Pump should be ok!
3) In logical orderthen the problem is a leaky injector, then repeated the procedure and applied45psi to the filter inlet (towards the fuel rail) surprise! Not leaking! And the fuel gauge remains at45psi
Then at this point achecked again the fuel diagram and there is not another elements in thepressure line. Dealership doesn't know.
Potentials
1) Another element notconsidered?
2) Remaining power onthe injectors from the ECU and leaking because are opened?
Your guys think that Iam missing something?
The ideas will be veryappreciated
Thanks Gabo
Last edited by Gaborover; 10-05-2013 at 03:25 PM.
Thread
Thread Starter
Forum
Replies
Last Post
ab4x4
General Range Rover Discussion - Archived
8
02-18-2015 02:22 PM
frederickshepard
General Range Rover Discussion - Archived
2
02-17-2014 09:09 PM
LandRoverNews
LR3
5
09-16-2011 03:44 PM
LandRoverNews
LR4
0
09-16-2011 05:45 AM
