2003 Sprinter Wont Start

Ring man

New member
I ordered e new pump.

Took the old one apart to see what it looked like, looked fine so I put it back together.

I filed it with fuel and put it back on with the gravity hose filled and when I cranked it fuel over filled the hose instead of sucking it in.
 
I ordered e new pump.
Buddy, you're guessing again.

Your vehicle is built out of many thousands of parts- the odds of you guessing correctly are pretty slim.

Did you order an aftermarket fuel pump, or a genuine Mercedes-Benz fuel pump? I'd hate to see you install any more problems into your vehicle.

Took the old one apart to see what it looked like, looked fine so I put it back together.

I filed it with fuel and put it back on with the gravity hose filled and when I cranked it fuel over filled the hose instead of sucking it in.
Your statement makes it sound like the fuel pump is pumping fuel, which is what fuel pumps are supposed to do.
 

Ring man

New member
Buddy, you're guessing again.

Your vehicle is built out of many thousands of parts- the odds of you guessing correctly are pretty slim.

Did you order an aftermarket fuel pump, or a genuine Mercedes-Benz fuel pump? I'd hate to see you install any more problems into your vehicle.



Your statement makes it sound like the fuel pump is pumping fuel, which is what fuel pumps are supposed to do.
To me i seems hat the check valve in the pump is letting the fuel back up the gravity hose, it should lower the fuel in the hose.

I ordered am OEM pump.
 

Midwestdrifter

Engineer In Residence
The LP pump is a gear type pump. It can only move fuel one direction. When they fail (which is rare) is usually low flow, not reverse flow. You can remove the pump and spin with with a drill on the bench. I am not intimately familiar with the plumbing on this unit, but there should be some details in the 03 service manual and training materials.
 

Nautamaran

2004 140” HRC 2500 (Crewed)
Are you certain the inlet and outlet hoses aren't reversed? If memory serves they use the same fitting.
LP pump draws in through the lower fitting, pushes out through the upper fitting. From 2003 service manual:
http://www.diysprinter.co.uk/reference/2003SprinterManuals.zip
OPERATION - LOW PRESSURE PUMP
The low pressure pump draws fuel from tank through fuel filter and supplies the high pressure pump. Fuel pressure at starter speed is 0.4 to 1.5 bar (6 to 22 psi.). A fuel pressure of 2.0 to 2.5 bar (29 to 36 psi.) is reached at idle speed. Fuel pressure is lim- ited to 3.5 bar ± .5 bar (51 psi. ± 7 psi) by the valve in the fuel delivery pump. This valve opens by over coming a spring force and allows excessive fuel to flow to the intake side of the low pressure pump. This diverted fuel flows into the return flow pipe through the fuel cooler back to the tank. As a result of this circulation, the fuel always remains relatively
cool.
-dave
 

Attachments

Ring man

New member
Thanks for all the links guys.

When I get the new pump I was thinking about filling it with fuel before I put it on, is that a good idea?
 

Midwestdrifter

Engineer In Residence
It needs to be VERY clean fuel. (filtered to 5 micron minimum) Otherwise I suggest using a hand vaccum pump to pull filtered fuel up through the filter. The injectors and pump are very sensitive to contamination, even contamination you can't see.
 

Ring man

New member
It needs to be VERY clean fuel. (filtered to 5 micron minimum) Otherwise I suggest using a hand vaccum pump to pull filtered fuel up through the filter. The injectors and pump are very sensitive to contamination, even contamination you can't see.
Thanks, I will run it through a coffee filter first.
 

Ring man

New member
I read in he manual that you should fill the pump, then i says you should attach a vacuum pump but is not clear on how to do this.

Where would I attach it?
 

Midwestdrifter

Engineer In Residence
To the outet of the pump I would guess. If you have a hand pump, you can just pull fuel up through the filter. Then pour that into the pump. Of you have a pump though, you can just install everything, and then prime via the pump output line.

I have not done this on the OM612 myself, so I can't off any tips.
 
B

billintomahawk

Guest
GT is just trying to get a rise out folks, and possibly make himself feel better/superior, while simultaneously feeding a deep seated need for attention. Add him to your ignore list and don't provide food for the troll.
MWD,

Thank you.

I was bit.

bill in tomahawk
 
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Ring man

New member
Well I am not having good luck, I replaced the low pressure pump, filled it by sucking fuel through the filter, and I still have no fuel at the injectors.

I just do not know what to check next.:frown:
 

Midwestdrifter

Engineer In Residence
You have confirmed fuel is flowing from the LP pump outlet? The LP pump is spinning at all? You can watch the cam gear through the oil fill location on the valve cover.
 
Well I am not having good luck, I replaced the low pressure pump, filled it by sucking fuel through the filter, and I still have no fuel at the injectors.

I just do not know what to check next.:frown:
As I previously stated:

I would strongly recommend that you stop guessing by randomly replacing parts for no reason. In addition to spending your money for no reason on parts that your vehicle may not need, you may actually be installing additional problems AND you're not solving your original Complaint. I have seen this happen many, many times.

Guessing is by far the most time-consuming and expensive method of vehicle repair. I would recommend diagnosis instead. Diagnosis is by far the least expensive and quickest method of vehicle repair.
 

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