[ChrizLoud]

Hello!

My 335D with newly installed hybrid turbo and Wagner intercooler is giving me an hard time. Not even fully tuned yet because until we can fix this problem. 1700bar fuel pressure is currently the set point value in the map but its fluctating and it can not hold it.

Giving me engine light and cuts out engine.



I have changed the following:

Fuel filter
In tank fuel pump
Rail Pressure Sensor (in front of fuel rail)


I need more ideas but my next take on this is:

Rail Pressure Regulator (in rear of fuel rail)


I have attached fault codes from Inpa and Testo log.

Testologs: https://minfil.org/w5q6q4b3b7/335D_Hybrid_testolog.zip

[335dsleeper]

I'd change the rail regulator immediately and go from there.

You can try unplugging the regulating sensor on the HPFP. I think when it's unplugged it maxes flow. The regulator might be faulty or your HPFP could be on its way out.

[kydiesel35]

I don't know though.... I had the same problems and it all turned out to be software. Your car was functioning correctly before right? Whats interesting is your using the same tune but getting plausibilities just after the hybrid install. Maybe your making too much of something that your car disagrees with...

The issues I had were all pointing to the rail, plausibility pressure too low, then I pulled a rail sensor code, all throwing me into limp mode. In a panic instead of swapping parts left and right (and many suspects) I went for a dyno tune...

What's strange is I too questioned the hpfp and lpfp as well but it turned out to be no hardware failures! Still problem free 30k later.

Hybrids can be tricky... but once you get those little bastards in line it's worth it.

[335dsleeper]

I'm not sure why hybrids would have much effect on rail pressure.

Map based system. Xxx fuel per xxx boost. Hybrids don't change things too much.

I'm curious what was causing issues in your tune.

[335dlci]

Where can I find testo for logging data?

[zackz]

Software problem...

[ChrizLoud]

Going back to my stage 2 map doing logs i can still see pressure drops but set point is not far away enough from actual rail pressure to throw codes.

[OmahaDZL]

Originally Posted by kydiesel35

I don't know though.... I had the same problems and it all turned out to be software. Your car was functioning correctly before right? Whats interesting is your using the same tune but getting plausibilities just after the hybrid install. Maybe your making too much of something that your car disagrees with...

The issues I had were all pointing to the rail, plausibility pressure too low, then I pulled a rail sensor code, all throwing me into limp mode. In a panic instead of swapping parts left and right (and many suspects) I went for a dyno tune...

What's strange is I too questioned the hpfp and lpfp as well but it turned out to be no hardware failures! Still problem free 30k later.

Hybrids can be tricky... but once you get those little bastards in line it's worth it.

I had the exact same experience when after my swap. I cant remember exactly what it was that was changed that stopped the issue from happening, but I know it wasnt either of the pumps....pretty sure it wasnt the regulator either...but dont remember 100%.

Think it ended up being clearing adaptations again but I am just not sure....its been so long and Ive been through so much stuff....sorry I cant be more clear on it.... I can tell you that it was not the pumps though!

[zackz]

Originally Posted by ChrizLoud

Going back to my stage 2 map doing logs i can still see pressure drops but set point is not far away enough from actual rail pressure to throw codes.

Again, software related problem, bad tune, or you are requesting too much fuel for your current setup.

Think about that...

[ChrizLoud]

Originally Posted by zackz

Again, software related problem, bad tune, or you are requesting too much fuel for your current setup.

Think about that...

Did you even look at the fault codes or the testolog?

I have pressure drops regardless of what map i'm using.

The stage 3 map is 1700bar railpressure but you can clearly see in the log that it's fluctuating up and down.

The reason the car throws code on the stage 3 map is that the setpoint and actual value is to far away. I tried again last night to confirm this and it eventually even throw a code on the stage 2 map in very high speed.

[ChrizLoud]

Originally Posted by OmahaDZL

I had the exact same experience when after my swap. I cant remember exactly what it was that was changed that stopped the issue from happening, but I know it wasnt either of the pumps....pretty sure it wasnt the regulator either...but dont remember 100%.

Think it ended up being clearing adaptations again but I am just not sure....its been so long and Ive been through so much stuff....sorry I cant be more clear on it.... I can tell you that it was not the pumps though!

I actually havent tried to clear adaption values but i doubt it would solve the problem. If you could remember what solved yours it would be awesome

[ChrizLoud]

Originally Posted by 335dsleeper

I'd change the rail regulator immediately and go from there.

You can try unplugging the regulating sensor on the HPFP. I think when it's unplugged it maxes flow. The regulator might be faulty or your HPFP could be on its way out.

If will try to un-plug the sensor on the HPFP. Thank you.

[zackz]

Originally Posted by ChrizLoud

Did you even look at the fault codes or the testolog?

I have pressure drops regardless of what map i'm using.

The stage 3 map is 1700bar railpressure but you can clearly see in the log that it's fluctuating up and down.

The reason the car throws code on the stage 3 map is that the setpoint and actual value is to far away. I tried again last night to confirm this and it eventually even throw a code on the stage 2 map in very high speed.

Yeah, I have checked your log and fault codes before my first reply...

Have you tried the stock map?

[pheno]

Nice logging! If you want to have more resolution I'd suggest to do another custom job with only the parameters you need. Now there seems to be some lag between requests in the .csv file

Here's sample video from my car.

[OmahaDZL]

Originally Posted by ChrizLoud

I actually havent tried to clear adaption values but i doubt it would solve the problem. If you could remember what solved yours it would be awesome

Man as far as I can remember thats the only thing that was done. I mean, we might have changed an injector....cuz I know I ended up with a bad one....but other than that we cleared all adaptations.....and the car stopped dying. We didnt change the tune, didnt change the pressure sensor, didnt change the pump...nothing like that.

[Nadir Point]

Clearing adaptations should always be a diagnostic step taken early in the process when dealing with spooky problems on these engines.

[ChrizLoud]

I have now replaced the in tank fuel pump. Brand new VDO! It did not help.
Have some one tried the DIS test yet? New fuel pump does not pass test either.

Fault-Set 1 - ( 232000 km)

battery voltage: 14.50 V
Coolant temperature: 87.27 deg C
Duty rail pressure control valve: 58.29 %
Engine speed: 4330.45 1/min
Injection quantity: 57.50 mg/Hub
Kraftstoffvorförderdruck: 188.32 mbar
Metering current control filtered actual current value: 294.68 mA
Rail Pressure Is: 1441.48 bar
Rail pressure setpoint: 1693.54 bar
vehicle speed: 82.91 km/h

Fault-Set 2 - ( 232016 km)

battery voltage: 14.34 V
Coolant temperature: 93.29 deg C
Duty rail pressure control valve: 60.65 %
Engine speed: 4661.44 1/min
Injection quantity: 93.74 mg/Hub
Kraftstoffvorförderdruck: 188.32 mbar
Metering current control filtered actual current value: 294.68 mA
Rail Pressure Is: 1228.80 bar
Rail pressure setpoint: 1693.54 bar
vehicle speed: 79.95 km/h

*** 4570:4570 ***
Fault-Set 1 - ( 232000 km)

battery voltage: 14.34 V
Coolant temperature: 88.27 deg C
Duty rail pressure control valve: 59.08 %
Engine speed: 3778.80 1/min
Injection quantity: 99.64 mg/Hub
Kraftstoffvorförderdruck: 188.32 mbar
Metering current control filtered actual current value: 648.29 mA
Rail Pressure Is: 1472.98 bar
Rail pressure setpoint: 1693.54 bar
vehicle speed: 101.66 km/h

*** 4610:4610 ***
Fault-Set 1 - ( 232000 km)

battery voltage: 14.34 V
Coolant temperature: 88.27 deg C
Duty rail pressure control valve: 56.71 %
Engine speed: 4302.87 1/min
Injection quantity: 99.64 mg/Hub
Kraftstoffvorförderdruck: 188.32 mbar
Metering current control filtered actual current value: 294.68 mA
Rail Pressure Is: 1276.06 bar
Rail pressure setpoint: 1693.54 bar
vehicle speed: 115.48 km/h

The test result is better but still not pass:

[DWR]

Interesting readouts. I assume duty on rail pressure control is really duty cycle on the volume control valve, yes? If so, those values do not look right. I certainly would not be worried about pumps when the duty cycle is not anywhere near maxed out.

[ChrizLoud]

That means we are probably looking at:

HPFP issue (worn out pump?)
HPFP flow valve (the valve/control sensor on the HPFP itself)
or in best case worn rail pressure sensor. (i tried 2 different sensors but the were used, maybe they gets problem reading high pressures when old?)

[lnxguy]

Was the car tuned before the hybrids and intercooler were installed?

If not, and this happened after the tune you should be looking a lot closer at the software.

[ChrizLoud]

Yes it was tuned before it was on stage II but when going back to that map i can see fuel pressure drops also so tune seems to be ok but the setpoint for rail pressure is lower in the stage II map than the stage III map so problem was not that noticeable before.

[335dsleeper]

Did you ever figure out this problem? I'm dealing with an amazingly similar situation.