Crank no start Mercedes sprinter 2007

Hello guys

I’m at a crossword on this Benz sprinter and before I finally decide to yank off this CDI 4 cylinder engine, I thought I should seek for help first

3 mechanics have worked on it with no headway

I’m using a xentry software for my diagnosis

I’m having low rail fuel pressure of 15bars instead of above 320 bars

Low pressure pump in the tank is working fine. Changed fuel filter

High pressure pump is very very low
I disconnected the connected steel pipe from the HPFP to the rail just in case if an injector is the culprit, but the pressure on the HPFP itself is too low

My tachometer doesn’t move an inch when I crank

I was about ordering for a new HPFP, but the entire job of taking off the whole front grill and radiator is the biggest drawback here. I’m also suspecting maybe the HPFP is not faulty. Maybe the ECU is programmed to cut off fuel supply if the vehicle has a crank and cam issues.

Xentry software says synchronization is faulty. I’m stomped on which direction to go now

Fuel delivery OR
Crank and cam

How do I solve this synchronization issue

H

Does the scan tool show RPM while cranking? If yes, will it run on Propane through the air intake?

If your cam timing is off it doesn't matter what a good HP Pump will do.

How does the Cranking cadence sound, do an Relative Compression test with an ignition sync.

Make sure your CKP and CMP signals are good.

In-cyinder Pressure Transducer with corresponding cyclinders spark sync will supply a ton of diagnostic info.

Put a scope on the HP fuel pump solenoid wires with a current clamp, is the PCM trying to control it?

Just a few ideas.

Thanks Paul

I just went back to check one of the videos I recorded during cranking

The RPM on the scan tool went from 0 to 188 with no propane or any starting fluid

The vehicle started when starting fluid was applied through the air intake but wouldn’t rev when the accelerator pedal is applied.

It shuts down once the starting fluid is taking off

The engine cranks very good and fast

I don’t have tools to carry out all the other tests

Looks like if the vehicle is able to get the injectors to open everything will be fine
But why then am I having a high injection quantity per stroke above the specified value

Wish there was a way this xentry software can pin point exactly the failing component

Before all this happened, I was having a hard start when engine is cold, but once the engine is fully warmed up to operating temperature of about 85 degrees Celsius then it starts very fast

The wiring of the cam checks fine

The crank sensor has two wires

With the wire harness unplugged, KOEO I’m having 2.45v on both wires, wondering if this is normal

Hey Paul
This next observation may just be the fix unless of course this Cam sensor work’s differently to the crank

So I watched a crank sensor video of a sprinter with 3 wires

My crank has two wires but my CAM has three wires

From that video of the crank sensor circuit diagnosis, I can see the reference and signal wires have 5v when connector unplugged, and still maintained those voltages with the connector plugged. The signal wire voltage was only pulled to ground with a 0-5v square waves on a good working sensor KOER
Unfortunately for my CAM sensor, the readings are ok when connector is unplugged, however the signal voltage drops to zero when the electrical connector is connected before cranking

During cranking the voltage then goes to 5v. Need to know what’s normal

When I pulled out the CAM sensor with the connector still plugged, the signal voltage is restored back to 5v, and as I touched the head of CAM with a metal then it drops to 0v

Looks like the CAM sensor head is already making contact direct contact with the camshaft once installed before cranking, which explains the signal voltage drop

What should be the timing start point for the CAM sensor? Should it make a direct contact with the camshaft before cranking

Or is the CAM and crank system designed to work in the opposite of each other

Am I missing anything?

Need to know if the vehicle has jumped timing, but why then did it start when starting fluid is applied

Xentry software says synchronization faulty KOEO
Synchronization RUNNING, then OK during cranking

Your YouTube video
“How to test a cam or crank sensor with a voltmeter - Hall effect type - (quick tips)

My cam sensor using a voltmeter behaves exactly like you have in that video. So I want to rule out the CAM sensor as r the culprit. Wish I had access to a lab scope

How about the 2 wire crank sensor
How do I troubleshoot this using a DMM

Also actual engine coolant temperature is at 31 and the specified value during starting should be above 60 (Celsius)
Could this whole problem be caused by a tired ECT sensor?
But eventually the temperature gets to 85 with time when the vehicle was still running. No issue of overheating
Ambient temperature here is around 30 which I believe the sensor is right about
Why then is the xentry software specifying 60 degrees Celsius at a cold start

I’m most grateful for your guidance. I’ve paid Mechanics 3 times already for their time without fixing the problem

I’ve directed all the mechanics I know to your channel

I am a member here, I am not the site's owner. Mr. Paul Danner a.k.a Scanner Danner is the owner, and the videos are his.

So I have a few more questions, was the HP pump removed? If it was, was it installed correctly? If it is a follower style; was the follower possibly removed?

Is the engine oil contaminated with fuel?

If the engine ran smooth on alternate fuel, timing would be good, so it is likely a sensor/PCM issue.

Thanks for the clarification and your help so far

More information before this crank and no start

Vehicle hard start when engine was cold and perfect start when fully warmed or even half warmed

Few days before this issue, vehicle would drag like starving for fuel when cold (loss of power) and then then suddenly picks up after like 5-10km when warmed

Glow plugs were changed a day before this issue, but cylinder 1 glow plug wouldn’t come out so I left that (2,3,4 were changed) I’m getting short circuit code for glow plug 1

The high pressure pump was never removed and no work ever done in that direction

I’m attaching pix of values 2 days before this no start issue.

Something caused the rail pressure to drop to 15bars instead of 320 bars during cranking

I don’t know if this is a valid test to pin point this on a faulty HPFP high pressure fuel pump

I took off the pipe supplying diesel from the HPFP to the rail and cranked the engine, the direct pressure from the pump is very low before even making its way to the rail

The oil is not contaminated with fuel

Any ideas the suspected sensors I should be looking at

@Paul P

I’m trying to rule out the possibilities of the following components causing my crank and no start

I took off the return lines on all injectors and there was not one drop of fuel coming out from the leak off ports OF THE INJECTORS during cranking
First day of crank no start with the return line taking off the injectors. The number 4 port on the return line (not from the return port of the injector) was the only port flowing with much diesel (1.2,3 had no single drop of diesel). It was strange why 1,2,3 ports on the return line would be dry since all the ports on the return line are connected together
Is this showing a stuck open injector number 4?

I’ve had this issue before where the vehicle would only start by applying starting fluid, and the culprit was one of the injectors. Changed the injector and the starting problem went away
I’ve tried to use my scan tool to see each injector volume but nothing changed on the scan tool.

I disconnected the 14mm bolt directly from the supply outlet port on the high pressure pump and the pressure was just too low with some air bubbles like water boiling

Is the removal of the 14mm nut a valid test of a failed HPFP or is this test throwing me in the wrong direction of a failed HPFP. Maybe if I didn’t open that port I would have directly chased injectors

Any ideas how this system is designed to work. Can’t find any peculiar information online as to how exactly this systems work and how to carefully isolate the exact fault.

Good day everyone

The crank and no start is really tearing me apart

I’ve installed another high pressure pump and the pressure is far better than the old pump but unfortunately vehicle still will not start

With KOEO rail pressure is still stuck at 11 on the scanner instead of over 300 at startup

Took out one of the injectors still connected to the rail and wire harness and it didn’t spray any diesel
Swapped it with a known working injector and still not spraying
But there was fuel pressure coming to the injector but unfortunately it’s not spraying any diesel

Injector wires unplugged

Injector 1. Two wires (0.01 and 2.5v)
Same for injectors 3 and 4

Injector 2 (2.5v and 2.67v)

I have no injector codes nor cam/crank codes
Now I have no idea how this system is designed to work

Any help to narrow down the problem will be much appreciated

Why is the scan tool showing 11 bars for the old HP pump that was barely pumping and still 11 bars for the new HP pump that seems to be pumping diesel to the injectors and why are the injectors not opening to spray diesel into the cylinder

Why am I not even getting any code for this crank no start problem

Last repair I did was changing my glow plugs and I was unable to change glow plug 1 that was stuck. I’m getting short circuit code for glow plug 1

I need any expert opinion that can simplify what uncle Mercedes Benz is doing on this sprinter with no DTC to give any form of direction

With the fuel pressure sensor on the rail plugged in, rail pressure specified is at 300-350 and the actual is at 11bars

With the fuel pressure sensor disconnected, rail pressure specified is at 380-420 and the actual is at 400 bars and still crank no start