Its started a week ago, while climbing a seep hill at the desert, the engine was cut off like the fuel ended.
Closing the switch and restart the engine, it start immediately with no hesitation, no pedal was needed.
while driving a steep slope down, no issue with engine, all is well.
Drove home for 100KM up and down on the roads, no problem occurred, normal gear change and top RPM for gear change was 4200RPM as normal from my 7 years experience with this car.

I can reproduce the cut-off each time I step on a high rock with my front left wheel, then the engine cut-off, doing the same with the front right wheel the scenario does NOT happen
Driving fast in the round-about fast enough (Left hand side driver) the car gets a big roll over to the right, the engine cuts off.

So I have two actions help me reproduce this engine cut-off:
1. Climbing a large rock with front left wheel.
2. Driving fast in a round-about.

I had some suspicious with the following:
1. Genuine Fuel filter - was replaced- symptom 1 was happening, symptom 1 was happening.
2. Replaced fuel pump - OEM Bearmach - symptom 1 was happening, symptom 2 was gone.
3. Bypass the Interia switch - symptom 1 was happening, symptom 1 was happening.

Maybe Fuel Pressure regulator?
Electric issue?

 

What do you mean exactly "closing the switch..........."

I run a 2003 TD5 and haven't experienced similar issues but your's sounds like a few possible issues, inertia switch defective, electrical issue or fuel pressure reg. The TD5 is common rail and therefore self priming so changing filter or pump should all self prime. My guess is a defective inertia shutoff switch or an intermittent electrical defect. Have you checked out the codes for defects?

 

"Closing the switch" - turn off starting switch with the key...

black smoke while engine starts to choke.
Same behaviour when fuel tank is 1/2 or full - DIESEL TD5

Replaced for a new BEARMACH OEM fuel pump - no change.

I have a NANOCOM connected, and right after the engine cut-out I get a message "all five injectors (1-5) output drive peak charge is too long".

Slided back from the steep rock I drove on with left front wheel to simulate the cut-off with engine off, closed starting switch and re-start, it start immediately.

I had some suspicious with the following:
1. Genuine Fuel filter - was replaced- no change, still cut-off.
2. Replaced fuel pump - OEM Bearmach - no change, still cut-off.
3. Bypass the Interia switch - no change, still cut-off.

all five injectors (1-5) output drive peak charge is too long

This is what I found on the www to check:

1. Check the ECU Earth - Not sure how to do this...
2. Check the Main Relay under the passengers seat - Not sure which relays.
3. Check for Oil on Red ECU Plug and Clean - Done, very little oil before cleaning - No change
4. Check Battery Voltage is Between 9V & 16V - Done, in range.
5. Test Injectors Using Nanocom - OK when idle
6. Check Cylinder Balances with Nanocom - balanced on idle - NOT balanced during cut-out.
7. Check both ECM Connectors - Both OK no oil - Done - No change
8. Use Injector Cleaner - liqui moly diesel injector cleaner super - Done - No change
9. Check Circuit Integrity from ECM to injector harness via engine harness connection - How to perform this


Any other ideas?

 

When is the last time you replaced the air filter?

 

Are you still using the EGR valve? it sounds like a choked up EGR that's inoperative under load with black smoke on start up ard dying out under load. Too much fuel ratio to air i.e. fuel/air ratio screwed up.

How many miles on the engine?

It may be injectors failing but I don't reckon so. Is there any excessive oil in the intercooler? Are there any codes related to the MAF sensor? Are there any codes related to the MAP sensor?

 

ECU earth is the ground for the ECU. This doesn't seem like it's mechanical. Idle the truck, and start at the ECU. Attempt to flex the harness from the ECU to the injectors. Seems like you have a short somewhere and when the chassis flexes, it makes contact and stalls the vehicle.

but I generally work on Mercedes so I can be wrong..

 

I had fitted a SAFARI snorkel 6 month ago ~ 5000KM since with air filter clean.
Assuming it's the air filter the engine would cut out much sooner while accelerating.
While on the roads, the TD5 engine climbs up to 4200 RPM and then shifts the gear, this is normal.
I had a 2800 RPM limit by accelerating about a month ago but this time it's the Turbo Wastegate Valve - PMK100130 issue, was resolved.


EGR is fitted, the black smoke is only when the engine is starting to cut off, I see the NANOCOM report the injectors are out of balance.
engine has ~ 330,000 KM.
Did not checked for oil in the intercooler, fitted the provent 200 about a year ago to reduce the oil coming back to engine.
MAF is new 5 month old, the VDO type one, no errors on the NANOCOM related to MAF.

I suspect as DGI07 noted " Seems like you have a short somewhere and when the chassis flexes, it makes contact and stalls the vehicle"

Is it possible while the car is on a severe side slope, the intercooler is being blocked by excessive amount of oil, blocking the air to the engine??? (attached sample picture).

 

Is that a steady climb to 4200rpm? A friend of mine with a Td5 had a very similar problem and it ended up being the air filter clogging when under full boost

 

You've got me beaten I think and generally I know diesels pretty well, especially the TD5.

My other gem may be the in the rocker injector harness, they have a regular known problem on the TD5 of leaking oil by capillary action back to the engine ECU sited under the hood next to the wheel jack. There is a modded injector harness to overcome this problem. The symptoms are a misfire or cutting out particularly under working pressure. Sorry, I'm running out of ideas for this phenomena, have you tried Googling the symptoms as someone may have experienced a similar malady.

I do hate being beaten.

 

Your ideas are very successful.
Further more, opening the intercooler hoses and seeking for tons of oil, gladly I didn't find a drop, dry as a desert as should be (2 years old turbo) so it's not the way to go.

I decided to go the "electric way" as I was told by several forum members all over the world (yes, UK, US and OZI...).
After verifying I don't have excessive amount of oil in the ECU red connector, I had removed all the sleeves surrounding the wires going from connector C0171 to the ECU, and closely examin for any physical damage, well I didn't find any, but I had uses excessive amount of carburetor cleaning spray all over the C0171 connector all over, having ANY trace of oil to come out, sprayed also the wires themselves, making it easier to observe for any physical damage without the greasy layer they had.

After cleaning all electrical connectors both C0171 engine harness side and ECU side C0158, i headed for the test drive.
As I was experienced from the past, climbing with the front left wheel high enough to cut-out the engine (~ 1 meter rock) this time, surprize, the engine was still running ! but with very slight misfiring.

Drove back home and realized the logic behind engine cut-off / misfiring while the engine was tilted to the right (left front wheel up, engine tilted to the right), the injector loom is soaking with oil under the engine cover.

No escape for the fifth injector loom replacement...