T1N Fuel Contamination, 2006 51k MH, what now?

I don't see any harm in what you propose.

With regards to the ECMs fuel pressure control, it has a few options. It can disable one of the three pump elements in the HPFP, it can change injector duration, etc. It is probably just opening the rail pressure solenoid a bit more.

The P0088 code appears to be a generic OBDII code. What menu are you using to read the codes? The right path is scan->euro->sprinter->901/902/903

I doubt damage to be likely, but have no data...
I agree with MWD.
The spike in LP Fuel pressure that you observed as the code sets suggests that the fuel flow is interrupted - like a water hammer in plumbing, which suggests that the FQCV is being closed in response to the high rail pressure, and the rail solenoid valve is being opened, but I’m guessing about that. A scope on the leads or a live data stream from the ECM would confirm it (I think the valve duty is visible on the actuator menu?) If the pressure remained uncontrolled the ECM would likely dump open the rail solenoid, close the FQCV, and hault injection, stopping the engine.
(I am not aware of a piston control scheme in the HPFP? I believe it simply pumps whatever fuel is able to enter, which the FQCV modulates)

-dave

without all the insight that Nautamaran shares here, but having crawled around lots of bilges...
and having operated peugeot and veedub diesels that encountered shi_ty fuel....
methinks you ought to drop the tank and clean it/ hose it out thoroughly,
since if there's s__t growing in there, there's no way in hell you'll be able to clean it out with biocides
or ANY kind of fuel additives.

it's also why i tend to buy fuel at the same station(s) every time i fill up (costco usually)

(I am not aware of a piston control scheme in the HPFP? I believe it simply pumps whatever fuel is able to enter, which the FQCV modulates)

-dave

Click to expand...

Today I learned that the OM612 (-2003 models) does use a solenoid to disable one piston in the fuel pump to reduce the amount of HP fuel produced and to reduce fuel heating. The OM647 (2004-2006) uses the fuel quantity control valve for this function, reducing the effective stroke of any pump cylinder attempting to draw in fuel while the fqcv is closed.

-dave

Outbound, thanks for reading my post, the initial post was long, apologies, I already dropped my tank twice, cleaned it the first time, and blew out the fuel feed line from the filter to the tank. MWD, I have not looked into the return lines or the Y, and I'm using a autel802MD to read codes and live data. I also replaced the fuel quantity valve for reasons explained.
Dave, your post on water hammer relating closing the FQV firmly supports what I'm seeing in the data as the event happens. You really do have a good mind for this.
My only fear at this point, is a full obstruction of the solenoid valve and fuel only being regulated by the quantity valve after startup and whatever potential issues that might pose. I know my LP system is clean on the supply side.
Thank you all for reading and taking the time to care and respond.
MATES, ILL update when I dig back in, after I sail this thing 1000 miles to sedona, if things continue with the same symptoms, methinks that rail has got to come off and cleaned best mecan....
Appreciative...Chris, Four corners

rkymtn said:

...
MATES, ILL update when I dig back in, after I sail this thing 1000 miles to sedona, if things continue with the same symptoms, methinks that rail has got to come off and cleaned best mecan....
Appreciative...Chris, Four corners

Click to expand...

A nice long drive.



My question would be whether to try another dose of yum yum juice or leave things as is. Adding a can of BG245 fuel conditioner over long run time might help to loosen things and clean...
or it could loosen things and cause a different problem.

I'd be tempted to throw a can in and roll the dice. I have no data.

vic

rkymtn said:

I know my LP system is clean on the supply side.

Click to expand...

However supply and return are constantly looped so any contamination from the return side will then contaminate the supply side. Just wanna say to make sure you're packing a spare fuel filter for that long drive because it doesn't take a whole lot of gunk to fatally plug a filter, especially with a known issue of contamination possibly containing algae.

Good luck and happy trails.

I was watching my gauges last night...
My FQCV settles in at 41% after warmup then doesn’t move much.
The rail solenoid then varies a LOT, anywhere from 20% to 60% depending on LOD, RPM, and rail pressure (4,500-19,500psi)
Your AutelMD802 can display these too... if your FQCV duty % is a lot higher that supports the theory that your rail solenoid is partially blocked.
Have a good trip - and I too would pack a fuel filter.
-dave