Need diagnostic assistance

I have a 2003 sprinter van, 2.7. The condition is extended crank times and even more extended when warm. It also has a rolling idle thing going on. Although I just signed up this site has already helped me tremendously. Only reoccurring code is no. 1 glow plug. Using a snap on scanner I have determined that my no start/extended has to with rail pressure. When cranking I can watch the the rail pressure slowly rise until it starts. With the crank sensor unplugged I see no rims on the scanner or on the dash as well as a related DCT. Unplugging cam sensor also sets a DTC code , not synced with crank position. Blocked off all five injectors as well as the spill test, even with blocked injectors still not enough rail pressure to start. Replaced high pressure pump and regulator prints, even though orings looked good. Same thing. So with the injectors blocked off and new hpp I am thinking faulty rail regulator. Also once engine is running with rolling idle rail pressure is jumping above and below commanded pressure spec. When at throttle commanded and sensed pressure are right with each other. Back to a smooth idle then it starts rolling again as sensed pressure starts jumping again. Hope someone can understand my rumblings enough to help me with this no code issue. Thanks

partsandservice said:

I have a 2003 sprinter van, 2.7. The condition is extended crank times and even more extended when warm. It also has a rolling idle thing going on. Although I just signed up this site has already helped me tremendously. Only reoccurring code is no. 1 glow plug. Using a snap on scanner I have determined that my no start/extended has to with rail pressure. When cranking I can watch the the rail pressure slowly rise until it starts. With the crank sensor unplugged I see no rims on the scanner or on the dash as well as a related DCT. Unplugging cam sensor also sets a DTC code , not synced with crank position. Blocked off all five injectors as well as the spill test, even with blocked injectors still not enough rail pressure to start. Replaced high pressure pump and regulator prints, even though orings looked good. Same thing. So with the injectors blocked off and new hpp I am thinking faulty rail regulator. Also once engine is running with rolling idle rail pressure is jumping above and below commanded pressure spec. When at throttle commanded and sensed pressure are right with each other. Back to a smooth idle then it starts rolling again as sensed pressure starts jumping again. Hope someone can understand my rumblings enough to help me with this no code issue. Thanks

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Hey Dennis here.
I can share with you lots of info so can some of the old stalwarts on this forum.
Why not give me a bell at my shop and I can go over some things, I would have writer's cramp listing possible causal conditions.
Cheers Dennis
7203441877

So I got a new rail regulator and the sprinter is back. After learning the fuel system I am impressed with the design and simplicity of this engine, this would be a great engine for a swap into a half ton truck. Thanks again.

Would You mind to share some details on this fix, I have an no start when warm issue that I thought was the injectors but when I run a test with the scan tool it shows all of them within specs, then the leak test shows some fuel on the 3/8" clear lines (1") but not enough to blame it on the injectors, I changed the fuel solenoid O-rings and nothing changed, I thought I had an air leak but it starts right up when cold every morning and will crank for 10 seconds when warm some times I have to crank it twice to get it to start and some times it will be warm I think this is going to be another episode and suddenly the engine starts right up. I'm lost right now on this issue and I would buy new injectors if it wasn't for the chance they may not be the problem and the fact they cost over $1k for a new set.

Thanks.

I will go through it but keep in mind that I am not a MB expert and a lot of the info I gained came as a result of this website. The fuel system is simple common rail. By monitoring the rail pressure and having an absence of when experiencing the no start condition I determined that the problem was defiantly a leak or loss of pressure in the rail. The rail would be considered anywhere between the outlet of the high pump all the way to the solonoid in each injector. I did the injector spill test and found minimal leakage. I also loosened all injection lines and placed a ball bearing in each injector line seat and tightened lines. At this point I have eliminated the injectors completely from the rail. Cranking the engine over while monitoring found extended crank time before rail pressure met the psi demanded by ECM to turn injectors on. So that leaves only external leak, high pressure pump, pressure regulator as source of the leak. First I replaced the hpp and that changed nothing. Upset at my self for choosing the more expensive part to replace first, I then installed the regulator and now it starts instantly. I tried to figure out how to do a spill test to determine which of the two parts was the culprit but could not developed on that was feasible to achieve. I though about doing a spill test at the vent line for rail regulator but that would introduce air into the system as the vent line directs overflow back into the hpp. I went with the pump first thinking previous filter changes by others could have damaged the the hpp with dry starts. I do have vast hydraulic diagnostic experience and this is nothing more than a hydraulic system , suction , pump , pressure relief , and actuator. Get this down and you also know how to diagnose a powerstroke same stuff. Did that help?

So what's easier this 'un or the Powerchoke?
Remember the latest rendition of the 6.4 has two rails and an HP Pump. HeUe's are history with the 6.4 !

Still prefer these two to the GM Isuzu beast in GMC's. What a horror!
Glad you nailed it!
Cheers Dennis

Got it, I just have to figure out how to do this test with My scan tool. Thanks.

Even though the 7.3 and 6.0 power strokes are a HUEI system that uses oil pressure for injection it is still a common rail. The Benz is much easier for access. I don't own any GM products and don,t plan on doing so. I have no experience with the 6.4. I repair heavy equipment for a living and the only automotive repair I do is on my own vehicles. I have taken in some outside powerstroke repair in the past but these customers have what I call diesel shock. A 6k bill for hpop pump and 8 injectors is something they were not expecting when they thought it would be cool to own a diesel pickup.

partsandservice said:

Even though the 7.3 and 6.0 power strokes are a HUEI system that uses oil pressure for injection it is still a common rail. The Benz is much easier for access. I don't own any GM products and don,t plan on doing so. I have no experience with the 6.4. I repair heavy equipment for a living and the only automotive repair I do is on my own vehicles. I have taken in some outside powerstroke repair in the past but these customers have what I call diesel shock. A 6k bill for hpop pump and 8 injectors is something they were not expecting when they thought it would be cool to own a diesel pickup.

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Yes--Absolutely!
I have see folk almost have a melt down when given an estimate or bill for that type of work.
Yes that's when the PU coolness disappears and the heat rage rises.
Cheers Dennis

partsandservice said:

... I tried to figure out how to do a spill test to determine which of the two parts was the culprit but could not developed on that was feasible to achieve. ...

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A search is often effective. If you use advanced search and highlight the T1N section only it narrows down the hits. I used "fuel+solenoid+test" as can be seen by the words in red highlight

https://sprinter-source.com/forums/showthread.php?t=27630&highlight=fuel+solenoid+test


vic

Thinking back on it, the fluctuations in the sensed pressure once the engine was running would more than likely have been caused by the regulator rather than the pump. Oh well at least it has a new pump now.