sprinter engine shut down

[robsmoke]

Hello, I have 2002 sprinter that has a problem that has me stumped. It starts ans runs fine but recently the engine will shut off under high load situations. I have replaced the fuel filter, fuel rail, injection pump (6months ago) and did and injector leak off test (which was fine). Nothing helps. When I am driving as soon as i give it 3/4 to full throttle it shuts down, not limp mode but a shut down requiring a re-start.
I am getting a trouble code of Fuel rail pressure (" leakage ") with my scan tool. Could it be a problem with the high pressure element shut off solenoid? also should i do a running injector leak off test? any ideas?
Thank you

 

[lindenengineering]

Well you state you have scanner!
What is the live data FIE info you are getting when the failure occurs ?
Dennis
Mechanic

 

[robsmoke]

FIE? i will have to set up and get a partener to watch

 

[lindenengineering]

FIE
Fuel Injection Equipment on the rig.
Dennis

 

[MillionMileSprinter]

Yeah, do a leak off test with the engine good and hot. Also get a helper to watch the clear fuel line coming out of the filter as you rev the engine and try to simulate a load on the engine. As you rev the engine more, the low pressure fuel pump works ever harder and any pinhole leaks that don't show at idle may appear. By leak, I mean air bubbles in the fuel line.

 

[MillionMileSprinter]

Also engine shutdown at full load on an 02-03 is classic injector failure. On those engines, when an injector stops functioning while driving, the ECU automatically shuts the engine down. And if the ECU is logging low fuel pressure, it stands to good reason that 'ye olde leak off test' is in order with a hot engine.

 

[robsmoke]

I did the leakdown test hot and they where all within spec. two of the injectors where borderline so i replaced those today. My scan tool shows rail pressure good with no load. I went for a test drive and it shut down again. the recorded event was code 1187-032 "leakage". the fuel rail pressure requested was 1350 bar and actual was 855. ???

 

[SneakyAnarchistVanCamper]

You need to start with step 1 of the diagnosis tree: The LP fuel supply. Air intrusion prevents fuel pressure from building to set pressure. Seeing as you have a 2002 with the suction lift pump, you should look closely for air bubbles in the line. Next, install a pressure gauge with a T fitting to monitor lift pump pressure during the event. Once lift pump pressure is verified during the fault then and only then can we move on to troubleshooting the hp system.


Did you replace the solenoid on the pump, or swap it over? The "high pressure element shut off solenoid" aka the quantity control valve "is used to shut off one of the 3 pump elements if fuel temp rises to scary high levels". As I understand, it also helps regulate rail pressure. Were it to fail, you might have a problem producing high pressures, so yes, I would think that would be a prime suspect, and I would think it would make actual rail pressure (edit) lower than set rail pressure, making the ECM think there is leakage going on.

Is your fuel temp reading abnormal?
Quick test for fuel quantity control valve: Park on a hill. Shut off engine. Floor it up the hill.

"Fuel quantity control is performed under the following
operating conditions:
² Approximately 30 seconds after the engine has
started
² Fuel temperature > 20°C (68°F)
² Engine not in deceleration mode"

"In order to adapt the
quantity injected, either the fuel rail pressure can be
adjusted by the fuel solenoid and quantity control
valve or the actuation time of the solenoid valves in
the injectors"

"The ECM limits
the fuel rail pressure when the engine is operating at
full load by way of the quantity control valve, and
quantity of fuel injected by the injectors."

 

[MillionMileSprinter]

I don't have a 612 Engine available here for me to check, but I'm pretty sure it doesn't have a quantity control valve on the high pressure pump. That wasn't introduced until the 647s in 04.
Have you checked for air leaks (bubbles) in the fuel lines? Again, since it only happens under load, you will need a helper to do this.

 

[robsmoke]

Yes I have, all they fuel lines are new and i have replaced the fuel filter with a non-water sensor style eliminating a big source of air leaks. I also checked that the high speed shut off solenoid was functional and not stuck. I am really at a loss here. I can only think it is the high pressure pump at this point. It does not leak but when monitoring pressures with my scan tool it always seems to lag a bit under what is requested. What are the symptoms of a bad ECM?