Close

Results 1 to 12 of 12
  1. #1
    Join Date
    Mar 2019
    Posts
    2
    Rep Points
    1.1
    Mentioned
    0 Post(s)
    Rep Power
    0


    Yes Reputation No

    Ran out of gas, now I have misfires under heavy acceleration

    As the title says....

    I did a stupid and forgot the car was running in the laneway, and let it run completely out of gas. Then of course, all of the hvac, stereo, lights, etc were still on and the battery went flat.

    Charged the battery, got gas, got it restarted, everything good....not so much.

    Now, whenever I do any heavy acceleration, it get misfires. Light to moderate acceleration is just fine, but as soon as it gets above 4k RPM, misfires again.

    If I continue to accelerate hard, the CEL will illuminate and I need to shut the car on and off again to stop the misfiring.

    Codes are cylinder misfires.

    So, my questions is, what did I $#@! up? Where to start? HPFP? LPFP? Injectors? Plugs?

    I don't want to start throwing parts at it until I get a bit of direction.

    Thanks for your help!

    I can post data logs or specific codes if need be. (Bimmergeeks ProTool)

    Cheers.

  2. #2
    Join Date
    Jul 2012
    Location
    Boston, MA
    Posts
    3,241
    Rep Points
    2,454.7
    Mentioned
    82 Post(s)
    Rep Power
    25


    Yes Reputation No
    Post the logs.

    I would hazard to guess you sucked up the muck at the bottom of the fuel tank and it clogged something along the way.

    You would hope the HPFP rail screen would catch it unless you removed the screen and drill out the HPFP for a VERY small increase in HPFP aka the ol false VTT HPFP upgrade/fix they sold.

  3. #3
    Join Date
    Mar 2019
    Posts
    2
    Rep Points
    1.1
    Mentioned
    0 Post(s)
    Rep Power
    0



    Yes Reputation No
    Logs and error.

    Seems to be localized to cyl 4.

    Swap injectors with another cylinder and do another pull?


    Can't post link to log because I'm a noob.

    Cylinder 4 misfires anyway.

  4. #4
    Join Date
    Aug 2018
    Posts
    72
    Rep Points
    112.6
    Mentioned
    1 Post(s)
    Rep Power
    2


    Yes Reputation No
    Best to have a log.

    The LPFP and HPFP are okay if it's just cylinder 4, but i guess you already figured this out.
    Did you have ANY cold start rough running or other issues before this?
    Obviously, fuel tank gunk won't impact sparks or coils, so injector would be my first guess.

    Before i'd pull anything apart (and replacing all the necessary injector seals), i'd try to get the car as warm as possible (not accelerating hard, just higher rpm's).
    Maybe, just maybe this heats the injector tips enough to burn it off..
    You can also try some Chevron Techron fuel system cleaner.
    If this doesn't help, you can try to swap injectors 3 & 4 and see if the problem moves to cylinder 3.
    Yes? Injector is toast.
    No? Keep searching..

  5. #5
    Join Date
    Jun 2016
    Posts
    155
    Rep Points
    256.1
    Mentioned
    2 Post(s)
    Rep Power
    3


    Yes Reputation No
    Possibly got a superknock from running lean and $#@!ed a ringland....
    Compression test to be sure.
    335I 545whp, Chinesium FCBO. AliExpress 16t turbos. JE forged pistons, FCP engineering forged rods, king sv bearings, Vargas spline lock crank hub built block. 2x cm7 meth injection. STOCK charge pipe.

  6. #6
    Join Date
    Aug 2018
    Posts
    72
    Rep Points
    112.6
    Mentioned
    1 Post(s)
    Rep Power
    2


    Yes Reputation No
    I think if you busted something mechanically in the engine, you would DEFINITELY notice it on cold start.
    These engines are really sensitive to everything on cold starts.

    Still curious if this is true or it's just under load?

  7. #7
    Join Date
    Oct 2013
    Posts
    169
    Rep Points
    209.4
    Mentioned
    11 Post(s)
    Rep Power
    3


    Yes Reputation No
    There's a ton of sediment at the bottom of tanks, I would pull the hpfp filter and check that....

    But that being said lpfps are cooled via fuel, you did a number on that poor guy running it dry :/ most other in tank pumps like to die after that.

  8. #8
    Join Date
    Jun 2016
    Posts
    155
    Rep Points
    256.1
    Mentioned
    2 Post(s)
    Rep Power
    3


    2 out of 2 members liked this post. Yes Reputation No
    I opened the tank on mine over 140k miles, no sediment. There's a pickup filter too. Really unlikely any dirt went to hpfp. It's not like an 80s car with a carb and ancient pickup.

    Also from knowing a few with blown motors, mine included before rebuild,they still idle smoothly as apparently the dme can increase or decrease the explosion strength of subsequent cylinders in the firing order to smooth out the running of the engine.

    Only inpa showed the issue in the rough running menu. You couldn't feel it.
    335I 545whp, Chinesium FCBO. AliExpress 16t turbos. JE forged pistons, FCP engineering forged rods, king sv bearings, Vargas spline lock crank hub built block. 2x cm7 meth injection. STOCK charge pipe.

  9. #9
    Join Date
    Jul 2019
    Posts
    15
    Rep Points
    54.0
    Mentioned
    0 Post(s)
    Rep Power
    0


    Yes Reputation No
    How much mileage is you 335i N54 at. Also is it 2007-08 or what year is it.

  10. #10
    Join Date
    May 2012
    Posts
    282
    Rep Points
    407.0
    Mentioned
    21 Post(s)
    Rep Power
    5


    1 out of 1 members liked this post. Yes Reputation No
    Being that they use the fuel to cool it, I'd bet you hurt the HPFP.

  11. #11
    Join Date
    Aug 2018
    Posts
    72
    Rep Points
    112.6
    Mentioned
    1 Post(s)
    Rep Power
    2


    Yes Reputation No
    Click here to enlarge Originally Posted by threetirtyfive Click here to enlarge
    Also from knowing a few with blown motors, mine included before rebuild,they still idle smoothly as apparently the dme can increase or decrease the explosion strength of subsequent cylinders in the firing order to smooth out the running of the engine.

    Only inpa showed the issue in the rough running menu. You couldn't feel it.
    Wow, i didn't know this!

  12. #12
    Join Date
    Jun 2016
    Posts
    155
    Rep Points
    256.1
    Mentioned
    2 Post(s)
    Rep Power
    3


    Yes Reputation No
    Click here to enlarge Originally Posted by atorrealba Click here to enlarge
    How much mileage is you 335i N54 at. Also is it 2007-08 or what year is it.
    2006 (UK) 155k miles.
    335I 545whp, Chinesium FCBO. AliExpress 16t turbos. JE forged pistons, FCP engineering forged rods, king sv bearings, Vargas spline lock crank hub built block. 2x cm7 meth injection. STOCK charge pipe.

Posting Permissions

  • You may not post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •