2003 wont start

TinkerTime

New member
Hello, I need some advice please.

I have a 2003, 3500 with 320K miles. I have been having issues with restarting when hot. Fires right up when cold, then when hot it takes several tries to re-fire. It then runs great.

I tried the injector leak down test, and all injectors are fine. I got it in to a diesel mechanic (not Sprinter trained). They diagnosed the fuel pressure sensor and fuel pressure regulator, both located on the fuel rail, as being bad. Unfortunately, since the fuel rail is located under the intake manifold the manifold must be removed to access the regulator in the rear. The estimate was $4K!

I am mechanically inclined, though not diesel specific, so for $4K I took on the challenge myself. No easy feat as there is NO room to work in the rear of the engine compartment.

I removed the wiring harness, fuel lines and intake manifold. Cleaned everything up and installed the new regulator and sensor. New intake gasket and put everything back together without issue.

When I attempted to restart, I turned over a bit sluggish and stumbled to fire up. I hadnt re-primed the fuel pump, so tried again. the second time it did start and run for about 30 seconds before it died. While it was running it was very rough and I had to manipulate the throttle to keep it going. It sounded like it had no power. Very flat and unwilling to rev up.

I recharged the battery. Re-primed the low pressure fuel pump and checked all the wiring connections.

Sadly, it will not start back up at all. In fact, now it doesn't even try to stumble into firing up. Just turn over without success.

At this point I am at loss. Nothing I did seems as though it should cause any issue with starting or running. Remove the intake manifold, replace the sensors, bolt it back together. The wiring harness is a no brainer, because you can only plug it in where the connectors are supposed to be.

What am I missing?
 

Nautamaran

2004 140” HRC 2500 (Crewed)
If it was rough and sputtering at idle you may still have residual air in the hp fuel rail and injector lines?
If there is any doubt try cracking open the hp fitting at #5 injector, crank to purge air, then retighten.
Repeat for #4 through #1 or until it starts and idles smoothly.
Be sure to use two wrenches: one to turn the collar, one to counter-hold the injector’s fitting

CAUTION: ALWAYS STAY WELL CLEAR OF PRESSURIZED HP FUEL LINE FITTINGS!
The pressure can spray fuel straight through your skin, causing poisoning and death.
(No joke. :thumbdown:)

The OM612 is sensitive to fuel leaks, especially if the LP pump is aging and can’t pull a prime.
Or the moon is in Taurus. Or it's Thursday... never could get the hang of Thursdays.
If you have a scanner, you can monitor the rail pressure during cranking and at idle.
It’s SAE PID# 23 hex; formula 10 x (256 A + B) kPa
The OM647 sees over 3000 kPa at idle;
I don’t know the typical om612 rail pressure but understand it is somewhat less.

-dave
 
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NelsonSprinter

Former Nelson BC Sprinter
I replaced the rear regulator on the fuel rail with a short socket wrench and mirrors.
I'm told coolant can drain into the cylinders upon removal of intake manifold, causing hard starting.
That has to be burned off causing steam exhaust. 1/2 second spray of starting fluid in Egr or addition of methyl hydrate into fuel filter might get things going.
 
B

billintomahawk

Guest
Did you remove the fuel filter?
Did you refill it with fuel before reconnecting and trying to restart?
The system will(is designed to) re prime itself but with mine it takes three or four tries to get going steadily and then a 10 mile run to clear all the air.

You should see fuel in the clear plastic line connecting the fuel filter to the low pressure pump.

And you shouldn't see air bubbles.

bill in tomahawk
 
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TinkerTime

New member
Good morning Dave,

Great advice. I just purged the lines to the injectors. All 5 were dry. I used a remote starter and disconnected the camshaft position sensor (CPS) so I could watch until the fuel came out, then immediately re-tightened the fittings. Everything is all reconnected (cps), and tried to start.

No go:thumbdown:

I did notice the water in fuel filter light on the dash, though the system does seem fully primed.

I have not drained the filter yet, but will do so then re-prime the whole system.

Assuming that is not the issue, what other possibilities?

Bill, thank you as well. No air bubbles in the lines. I feel pretty confident the whole system is purged of air now.
 

TinkerTime

New member
Update.

I decided to start over from ground zero on the fuel. I drained the High/low pressure lines all the way back to the fuel filter, and drained the filter itself. Using a suction pump I refilled the filter and bled the air out. Next I bled the fuel up to the low pressure pump to the outlet side. Finally I disconnected the CPS and used a remote starter button to crank fuel to each of the injectors. Starting at cylinder 5 and working forward. I cranked each until a steady stream of diesel was coming out, then quickly re-tightened. Reconnected the plug to the CPS. Lastly I shot some starter fluid into the EGR.

When I cranked it to start, it stumbled (starter fluid), but did not fire. Subsequent tries seemed like maybe it was considering firing up, but by the third or fourth try, it was clear it was not to be.

I rechecked fuel at the injectors, and no air, all fuel. The fuel lines are all clear of air. I double checked the connectors at the new sensors too. All looks good.

Recall that it did initially fire up and run for about 30 seconds, but nothing since.

I am totally stumped.
 

Nautamaran

2004 140” HRC 2500 (Crewed)
What electronics tools do you have access to?
If the fuel is no longer a suspect (can you watch the rail pressure while cranking?) then move along to the prerequisite sensors and actuators: crank and cam position sensors. Fuel rail pressure sensor. Fuel rail relief solenoid. HP Pump quantity control valve. etc.etc.etc.
The ECM needs to sync the crank and cam, and see sufficient rail pressure before it will trigger the injectors. Ensure it’s completing those prerequisites.
If your tach doesn’t twitch during cranking, the crank sensor is suspect;
if it does move on to the cam sensor.
If rail pressure doesn’t climb quickly look at the relief solenoid.
If the pressure doesn’t register look at the sensor.
The quantity valve is on the hp pump and doesn’t operate during the first 30 seconds after start, but since it shuts down fuel flow it can prevent starting.

You’ve just replaced the rail relief solenoid and sensor, so by the “look at what you did last” axiom you should review your work there first. Your original problem may have been the wiring rather than the hardware, and jiggling the connectors has exacerbated the issue rather than solved it.

These engines run on electrons as much as fuel and air... unfortunately electrons don’t leave puddles when they’re leaking.

-dave
 
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TinkerTime

New member
Possibly WIF. Not now though for sure as I drained the filter and all the lines to the injectors. Then reprimed them all the way back to the injectors. No water, no air. Still wont start.

Dave, I dont have access to any electronic diagnostic equipment. However, I am thinking its possible it could be something other than fuel. The camshaft position sensor is new. All the connectors and wiring seemend to be in good condition, though things did get moved around quite a lot. I am a bit suspect of the replaced sensors as they are not Bosch.... I will do more digging.

Thank you for the ideas so far.

Will-
 

Nautamaran

2004 140” HRC 2500 (Crewed)
Even if you can only check the wires for continuity it may be helpful?
A simple test lamp and a length of wire...
Then you’ll know if there is wire between the sensors and the ECM (it’s above the hood release in the cab)

(A scan tool quickly pays for itself, if not in avoiding diagnostic fees, then in goodwill from letting your neighbors using it... ;-)
CA seems relatively thick with T1Ns... maybe someone near you would barter with you for their help?

-dave
 

TinkerTime

New member
Good morning Dave,
Yes, both camshaft and crankshaft position sensors are connected.

I do have a continuity tester and test light. I will work my way through the wire connections next. My gut is telling me this is something simple thats just being overlooked. Thank you for the assistance.

Will-
 

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