[DKX4///M]

Formerly ASE Cerified Tech here...Trying to diagnose a huge power reduction/limp mode issue with M2...

OK bottom line FBO, NGK Plugs, Bootmod3 stage 2

Symptoms: Drivetrain Malfunction, Misfires (severe) worst in Cyl 1&6...Excess Fuel Coming out of Exhaust...Started months ago, wasnt gettin primary 02 reading from primary 02...02 short to ground and 02 heater short to ground were the 2 codes...Did continuity test on harness and ground...no short in harness...figured DME or sensor, replaced sensor...no difference...switched up coil packs, still cyl 1 and 2...

Checked fuel rail pressure via torque, about 1000psi at high idle (1000 rpm) maxes at 2800 psi at 3500-4k rpm and the car flat lines there...

Personally I think its LPFP, why? BC I tuned car immediately run higher boost, and used 30-40% e85 for a good amount of time unaware of the fuel volume issues with n55 system...also been running tank low alot and ran out of gas a week b4. and possibly with 02 sensor not reading , open loop probably had the car run rich for saety reasons..I also drive hard...car has 12k miles figured LPFPs been working at 100% PWM all 12k lol...

Anyone experience this? car spudders n misses,uses a ton of fuel...killing the plugs...

Background: So far I replaced plugs, 02 sensor....Im worried DME has physical damage and / or LPFP or maybe even hpfp...Whats target rail pressure , ballpark? should it go higher than 2800 PSI...can it reach these pressures if LPFP is bad? Do the fuel pump relays often burn out? Someone help me out please??

[M3 Adjuster]

Originally Posted by DKM2Power

Formerly ASE Cerified Tech here...Trying to diagnose a huge power reduction/limp mode issue with M2...

OK bottom line FBO, NGK Plugs, Bootmod3 stage 2

Symptoms: Drivetrain Malfunction, Misfires (severe) worst in Cyl 1&6...Excess Fuel Coming out of Exhaust...Started months ago, wasnt gettin primary 02 reading from primary 02...02 short to ground and 02 heater short to ground were the 2 codes...Did continuity test on harness and ground...no short in harness...figured DME or sensor, replaced sensor...no difference...switched up coil packs, still cyl 1 and 2...

Checked fuel rail pressure via torque, about 1000psi at high idle (1000 rpm) maxes at 2800 psi at 3500-4k rpm and the car flat lines there...

Personally I think its LPFP, why? BC I tuned car immediately run higher boost, and used 30-40% e85 for a good amount of time unaware of the fuel volume issues with n55 system...also been running tank low alot and ran out of gas a week b4. and possibly with 02 sensor not reading , open loop probably had the car run rich for saety reasons..I also drive hard...car has 12k miles figured LPFPs been working at 100% PWM all 12k lol...

Anyone experience this? car spudders n misses,uses a ton of fuel...killing the plugs...

Background: So far I replaced plugs, 02 sensor....Im worried DME has physical damage and / or LPFP or maybe even hpfp...Whats target rail pressure , ballpark? should it go higher than 2800 PSI...can it reach these pressures if LPFP is bad? Do the fuel pump relays often burn out? Someone help me out please??

I'm old school but there are a lot of items that concern me in your report.

"Running tank low a lot"
" ran out of gas"
" e85"
" I tuned car "

Addl info needed

Time frame for when items were replaced ?



Disclaimers:

1) Not a mechanic.
2) I Didn't sleep at a holiday inn last night.
3) Recommend KISS method.


-Confirm vehicle battery is in good working order.
-Install six fresh OEM spark plugs and check compression at each cylinder.

If compression test checks out dance a jig!

Replace ALL 02 sensors with known good sensors.

Next I would verify spark at each cylinder - replace coil packs if needed.

Then I would consider confirming fuel pressure level from LPFP.

[DKX4///M]

Originally Posted by M3 Adjuster

I'm old school but there are a lot of items that concern me in your report.

"Running tank low a lot"
" ran out of gas"
" e85"
" I tuned car "

Addl info needed

Time frame for when items were replaced ?



Disclaimers:

1) Not a mechanic.
2) I Didn't sleep at a holiday inn last night.
3) Recommend KISS method.


-Confirm vehicle battery is in good working order.
-Install six fresh OEM spark plugs and check compression at each cylinder.

If compression test checks out dance a jig!

Replace ALL 02 sensors with known good sensors.

Next I would verify spark at each cylinder - replace coil packs if needed.

Then I would consider confirming fuel pressure level from LPFP.

Thanks for your response...

To be more clear I didnt tune cars, I can and will be making a custom map down the line but right now im on Bootmode Stage 2 OTS tune...

I did replace primary 02...Secondary 02 will not affect running its just there to tell you if catalytic converter is working but with tune its not even monitered as i have a catless dp...

i was running 30-40% e85 so 25-30% ethanol the first few thousand miles (after break in) which is supposedly OK..But knowing the propertys of ethanol and the tremendous volume (almost double) and corrosive effects and now learning the stock pumps are maxed on 93 octane and stock boost...Obviously the pumps have been pushed hard for a while now...

All plugs were replaced by me a few days ago, it improved a bit and then is getting worse...still 50% or less power...cyl 1 and 6 the 2 furthest from TB..

I switched coils to see i the cylinder misses changed amd still 1 and 6 so not coil not plugs...im getting upto 2800psi fuel pressure at the rail (which i dont know stock target) im trying to find out...

Oddly Bootmode dash board when trying to compare HPFP target with reading they read 0...in fact all things related to fuel are reading 0...very strange but in torque and other 0bd apps i am getting fuel rail pressure...

im also getting 0 voltage at lpfp (reading) im going to take cover off this weeknd and use a voltage meter to see if its getting power...

Yes I have been letting the tank get low bc after LAMBDA READING STOPPED to DME the cars been horrible on gas so i was always low and refilling and i drive hard..

I REALLY WANT TO SUSPECT COMBO O DME CLOSED LOOP FUEL TARGET CIRCUITS (02 CIRCUITS) CAUSING RICH MIXTURE ON ANALREADY OVER TAXED OVER BOOSTED LPFP (ESPECIALLY WITH ETHANOL AND RUNNING TANK LOW) THATS A RECIPE FOR DESTRUCTION.

DOES ANYONE KNOW TARGET RANGE FUEL RAIL PRESSURE?

DOES ANYONE KNOW I THE CAR CAN RUN WITH NO LP FEED?

CAN THE CAR PUSH 2800PSI IF HPFP IS FAILED BY HIGH VOLUME LPFP PUSHING FUEL INTO TINY FUEL RAIL???

[SeanWRT]

On BM3 OTS,

HPFP targets 2880psi and actual normally does anywhere from 2200~3000psi.
LPFP should do 84psi flat.

You need to look at log to tell which one is wrong.

[DKX4///M]

Originally Posted by SeanWRT

On BM3 OTS,

HPFP targets 2880psi and actual normally does anywhere from 2200~3000psi.
LPFP should do 84psi flat.

You need to look at log to tell which one is wrong.

Thank you bro...

thankyou so much...

Strange thing is Bootmod3 Dash isnt displaying or logging ANYTHING related to the fuel system, everything says and logs 0...I think im on the newest frimware, a Rob (Fsociety) told me to try w my laptop instead of agent...

I got my Rail pressure by using torque and M Performance Drive Analyzer...Seems its on target...My onky question is how could the hpfp do its jon properly without the lpfp working, so i almost want to say something else is the issue here...Very confused.

[M3 Adjuster]

Originally Posted by DKM2Power

Thank you bro...

thankyou so much...

Strange thing is Bootmod3 Dash isnt displaying or logging ANYTHING related to the fuel system, everything says and logs 0...I think im on the newest frimware, a Rob (Fsociety) told me to try w my laptop instead of agent...

I got my Rail pressure by using torque and M Performance Drive Analyzer...Seems its on target...My onky question is how could the hpfp do its jon properly without the lpfp working, so i almost want to say something else is the issue here...Very confused.

Definitely test and check the pumps or any sensors providing readings.

It sounds like the lpfp may have failed , giving you zero readings ? . The HPfp is probably going crazy trying to do it's job and then gives out as it cannot ultimately do all the work.

[DKX4///M]

Originally Posted by M3 Adjuster

Definitely test and check the pumps or any sensors providing readings.

It sounds like the lpfp may have failed , giving you zero readings ? . The HPfp is probably going crazy trying to do it's job and then gives out as it cannot ultimately do all the work.

I would agree, however I believe the 0 ratings are a failure to read, not actual..I say this bc HPFP (target) HPFP (actual) lpfp voltage lpfp prssure (actual) and target, even fuel temp are ALL READING 0 on Bootmod3 software....Other OBD software (torque, dash command, and M Drive Analyzer are all indicating proper fuel rail pressure...Also the Pump isnt crashing, the car is in a constant reduced power state...

Even when I reset DME Adaptations and clear codes with bootmod3 or Carly (which finds deep and historic codes) when i turn on ignition for the first time i get the drivetrain makw b4 the engine is started....This tells me its an electrical issue...not a hardware problem...

Losing my mind.

[DKX4///M]

I updated OBD Agent Software and then tried data logging fuel PIDs on my Laptop...Heres what i meant by fuel related PIDs at zero, AFR stays at about stoichometric...(Not working) no matter what...u can here the horrible misses and cyl 1 and 6 not working (boxer engine sound) and the unburnt fuel exploding (backfire on engine decceleration...

[NO_USER_]

sometimes via the dashboard some values show 0, but if you datalog they won't be 0 and it'll show the true value...

idk why it does that

[DKX4///M]

Originally Posted by inline6ax

sometimes via the dashboard some values show 0, but if you datalog they won't be 0 and it'll show the true value...

idk why it does that

Thats very good to know, i will try tommorow, thank you...

I did try datalogging with the OBD on old sotware and it wouldnt even show the parameters i selected (ONLY DEFAULT)...But good to know that may not be part o the problem, and if I can log I can narrow this issue down very quickly...

I'll let you know what happens and post the log if it works...

[NO_USER_]

Originally Posted by DKM2Power

Thats very good to know, i will try tommorow, thank you...

I did try datalogging with the OBD on old sotware and it wouldnt even show the parameters i selected (ONLY DEFAULT)...But good to know that may not be part o the problem, and if I can log I can narrow this issue down very quickly...

I'll let you know what happens and post the log if it works...

I also noticed once for me, some of the parameters I had chosen in the dashboard would NOT show in my datalogs. I suggest you reset both the dashboard AND datalog parameters to default (that's what fixed it), incase it still doesn't show. Then choose any additional parameters in the datalog settings, but do not touch the dashboard, just leave it at default.

This is just what I've experienced.

[DKX4///M]

I didnt know thw two were seperate...I did reset to deault, but I though it datalogged what ever was on dash, that explains why none o my new parameters were showing up...

As for LPFP straining trying to keep up...in my gut i feel that is whats going on...its def been abused..since break in bc jb4 and open cat, to open 3" exhaut dump (boost activated...ive dealt with bost spikes over 20psi...It showed as high as 22 in some instances (which i thought the tmap only read to 20psi...but the turbo would spike and bc of zero back pressure it actualy mpved the stock turbos ve (efficiency range) about 1 psi higher...bc the rapid heat exhauted and no back pressure, the turbo could push a bit more air without heatsoak, especially after fbo....and the car runs SLIGHTY better with a full tank...

Has anyone here had a bad lpfp and still have it remain driveable? Thats the only thing i dont get,,,I would think itd be dead in the water especially direct injection...but weak fp would also explain why 1 and 6 (cy furthest rom fuel ines are getting unvaporized fuel seeminly)...

I need one anyway witj al my mods and tune so i will prob replace that this week wit a fuel it stage 2 but then i have to figure out the 02 short to ground codes too...So daignosis or me is about process of elimination...Im pretty much narrowed to loose dme connections , fried or damaged dme and or failing fuel pump...
Any more advice or just experince witht this would help but thank u

after lpfp, bringing car to non dealer bmw specialist

[PackPride85]

Try flashing back to stock.

[SeanWRT]

Do not jump into conclusion until you see from log it's LPFP.

I have yet to see a case where lpfp fails to keep up on stock turbo power level.

BTW, what does the code read?

[DKX4///M]

Sean there are many many codes in almost every control module in the car, KOMBI, FEM, NBT,DME, CAS etc...

Before going to shit it read 2 DME codes...
Primary O2 short to ground
primary 02 heatercircuit short to ground

Used continuity meter to find continuity between any 02 wires and ground...nothing...replaced anyway, still codes and no LAMBDA reading...

I did remove JB4 and flash bootmod3 to stock...

There is no LPFP pressure sensor so I guess i would test voltage to it and ind a shrader valve b4 the hpp and testin manually...when i turn ignition on i do here the fuel pump prime for about two secs so it hasnt 100% .ailed

[DKX4///M]

Im sorry to fully answer ur question I can tell you the dme now has so manycodes|

misfires mainy cylinder 1 and 6, some fuel code, lean readigs, rich reading...Ill screen shot everything tomm...

Important to note when i clear the dme and clear codes the DT MALFUNCTION comes on again before engine starts, indicating an electrical component failure...

[ZPrime]

Not sure why you're posting all of this in the main discussion forum instead of over in engine/exhaust/tuning section?

[DKX4///M]

When i acces from my mobile device the forum seems a very very different layout ...I post it there with a link to this thread

[DKX4///M]

Threads Moved to engine / drivetrain/ tuning...Picking it up there n will provide a link shortly...

[DKX4///M]

And SEANWRT

Here are all of the codes both historic and current right after i cleared everything...

CARLY DEEP DIAGNOSTIC
----------------------------------------------------------------------------

Apparently no Fuel Pressure codes

[DKX4///M]

just noticed there is a code for the flexray bus which I THINK is the connection between main harness and DME...which is what I initially suspected...

[cookiesowns]

Originally Posted by DKM2Power

just noticed there is a code for the flexray bus which I THINK is the connection between main harness and DME...which is what I initially suspected...

Give me a PM, I can help you remotely this weekend.