Results 1 to 15 of 15

Thread: Letting the smoke out (pump)

  1. #1
    Join Date
    Jan 2012
    Location
    Upstate South Carolina
    Posts
    319
    My Cars
    1996 840Ci / 2007 B7

    Letting the smoke out (pump)

    Finally got my fuel pump out (after spilling quite a bit of gas all over the garage floor and top of the fuel tank). When I apply 12V to the pump contacts, the black wire terminal immediately starts smoking, looks like it's melting the insulation. No pumping sounds at all. I didn't try to switch polarity on the power source because I didn't want further damage - negative pole on the battery was sending to the black wire. Is the pump completely toast? Salvageable with some seafoam? I'm just testing it wrong?



  2. #2
    Join Date
    Dec 2013
    Location
    San Antonio
    Posts
    712
    My Cars
    850,76 2002 &530,84 633
    I can't help you with the wiring but if you are using the right polarity and pump is not running then its probably seized. Seems like it would run either direction if current is reversed or not. I would probably buy a can or two of Seafoam at wallyworld, pull off filter, and let pump stand in fluid for several days and see if it frees up.

    And, pump should not be run 'dry' from what others have mentioned on here.

  3. #3
    Join Date
    Jun 2008
    Location
    SF Bay Area
    Posts
    3,778
    My Cars
    Supercharged 850ci
    Pump is dead. I have a new one left over, sent you a PM.

  4. #4
    Join Date
    Dec 2006
    Location
    Sunny Cali,
    Posts
    8,730
    My Cars
    6.5 second 69 Camaro
    I just gained more appreciation for LHM,) Your carrier looks to be in good shape.
    Last edited by 8eights; 03-13-2018 at 11:51 PM.

  5. #5
    Join Date
    Sep 2008
    Location
    Santa Barbara
    Posts
    3,462
    My Cars
    91 Dinan860 & 91 850 6sp
    1. Do NOT run the pump when it isn't submerged in gas. NO NO NO. Never.
    2. Replace pump. (see #1)
    3. If that pump ever was any good, it most assuredly isn't now... hence the smoke.
    4. Replace pump. (see #1)
    5. Did I mention not to dry run the pump? Not Ever.
    '91 Dinan 860 Stage III (new 6L engine)
    '91 Dinan 850 TT stage III (brand new engine) 21st Century Tech meets 18th Century Dinan...
    '91 850i 6sp (mint) (sold)
    '90 Dinan 750iL TT stage III (Guido - The Beast)
    '94 850 CSi The Detroit Auto Show car (restored to factory perfect) (sold)
    '96 850Ci, The George Carlin car
    ''73 3.0 csi, '08 535i, '03 X5 4.6is
    ...and a few other non BMW cars

  6. #6
    Join Date
    Jan 2012
    Location
    Upstate South Carolina
    Posts
    319
    My Cars
    1996 840Ci / 2007 B7
    Anything special for a wire submerged in gasoline? Or can I just use regular wire that I already have for other purposes?

    What's LHM, 8eights?

    Also, what is so special about this pump that even a second or two of dry running would be so detrimental. I think it was dead already, and was trying to test to see if it even spun... What happens if you run out of gas? Won't the pump continue to run dry at that point?

    Quote Originally Posted by CDO5OO1A View Post
    <-- What he said. AND wire will NEED to be re-terminated and the end of the wire that got hot cut off. Once copper gets that hot it loses a percentage of its conductive properties.

    At least the first inch looks toasted.

    The filter at the bottom looks like it might be split too.

  7. #7
    Join Date
    Jun 2008
    Location
    SF Bay Area
    Posts
    3,778
    My Cars
    Supercharged 850ci
    Quote Originally Posted by Spandrel View Post
    Anything special for a wire submerged in gasoline? Or can I just use regular wire that I already have for other purposes?

    What's LHM, 8eights?

    Also, what is so special about this pump that even a second or two of dry running would be so detrimental. I think it was dead already, and was trying to test to see if it even spun... What happens if you run out of gas? Won't the pump continue to run dry at that point?
    You can use regular wire. Running a pump dry usually damages the pump or shortens it's life span.

  8. #8
    Join Date
    Sep 2008
    Location
    Santa Barbara
    Posts
    3,462
    My Cars
    91 Dinan860 & 91 850 6sp
    I'd use a couple of layers of quality heatshrink to rehab the oem wire if it were me. Way better than a splice. Hot or not, that wire is more than healthy enough to run the pump

    When you run out of gas, there is still enough gas in the pump for lubrication, it won't spit it all up the tube when it stops coming in. No dry pump runs, please
    LHM = Limp Home Mode, or running on 6 cylinders by design
    Last edited by cartoonz; 03-15-2018 at 11:39 AM.
    '91 Dinan 860 Stage III (new 6L engine)
    '91 Dinan 850 TT stage III (brand new engine) 21st Century Tech meets 18th Century Dinan...
    '91 850i 6sp (mint) (sold)
    '90 Dinan 750iL TT stage III (Guido - The Beast)
    '94 850 CSi The Detroit Auto Show car (restored to factory perfect) (sold)
    '96 850Ci, The George Carlin car
    ''73 3.0 csi, '08 535i, '03 X5 4.6is
    ...and a few other non BMW cars

  9. #9
    Join Date
    Dec 2006
    Location
    Sunny Cali,
    Posts
    8,730
    My Cars
    6.5 second 69 Camaro
    Quote Originally Posted by Spandrel View Post

    What's LHM, 8eights?
    As Cartoonz mentioned, The ability to drive the car with a dead fuel pump because 2 pumps are available, 1 per each bank for V12's So you can still crawl to safety and further with half a engine.

  10. #10
    Join Date
    Jan 2012
    Location
    Upstate South Carolina
    Posts
    319
    My Cars
    1996 840Ci / 2007 B7
    Thanks, Ed. New one is not an exact replacement as it doesn't have the retainment ridge below the top to secure it in the carrier - zip ties will suffice, I hope. Made a guess at polarity that the larger screw was negative in the same way the larger screw on the original unit was negative. Also had to repair one of the rubber dampers (zip tie again - through both remaining rubber parts to maintain function). Ended up splicing the negaitive wire that was smoking using an inline splice, solder and some heat shrink tubing. Looks ok. About to install and find out if it works.





    Quote Originally Posted by dragon850 View Post
    Pump is dead. I have a new one left over, sent you a PM.

  11. #11
    Join Date
    Jun 2008
    Location
    SF Bay Area
    Posts
    3,778
    My Cars
    Supercharged 850ci
    Well, did it fire up? That install should be good enough..

  12. #12
    Join Date
    Jan 2012
    Location
    Upstate South Carolina
    Posts
    319
    My Cars
    1996 840Ci / 2007 B7
    It did!!!! Three and a half years in the middle of my garage and it moves under its own power!

    (No power steering, battery light and trans fail safe (still needs fluid after 8 liters in. Don't understand that one), but I'll take the progress!)

    Quote Originally Posted by dragon850 View Post
    Well, did it fire up? That install should be good enough..

  13. #13
    Join Date
    Jun 2008
    Location
    SF Bay Area
    Posts
    3,778
    My Cars
    Supercharged 850ci
    Quote Originally Posted by Spandrel View Post
    It did!!!! Three and a half years in the middle of my garage and it moves under its own power!

    (No power steering, battery light and trans fail safe (still needs fluid after 8 liters in. Don't understand that one), but I'll take the progress!)
    Nice!! Good to hear!

    Sent from my SM-G892U using Tapatalk

  14. #14
    Join Date
    Feb 2010
    Location
    Hampshire UK
    Posts
    8,869
    My Cars
    99 840ci Sport Indv
    About time too!
    Timm..2007 E64 650i Individual Sport..1999 E31 840ci Individual Sport..ex owner of 2000 E38 740..1999 E38 740i V8 M62..1998 E38 735i V8..1993 E32 730i V8..1988 E28 518i


    My BMW Repair YouTube Channel
    My Current 840ci Sport Individual
    My Current 650ci Sport Individual
    My E31 Repair and Information Website
    My E38 Repair and Information Website
    My E63/E64 Repair and Information Website

    Chase - Heroes to a generation

  15. #15
    Join Date
    Jan 2009
    Location
    Orlando, FL USA
    Posts
    1,209
    My Cars
    91 850
    Congrats on the progress...we all know the feeling too well. As Timm would say, "time for a cup of tea".

Similar Threads

  1. Engine idle rpm rises when I let the clutch out. Anti-Stall System?!?
    By shanecconn in forum 2006 - 2012 (E90, E91, E92, E93)
    Replies: 2
    Last Post: 09-28-2017, 03:29 PM
  2. Clink and thud when letting the clutch out
    By OutAndBack in forum 1988 - 1996 (E34)
    Replies: 4
    Last Post: 03-01-2013, 05:40 AM
  3. Replies: 2
    Last Post: 02-13-2008, 02:28 AM
  4. So im hearing a slight rattle behind me when I let the clutch out...?
    By Zaf///Mroadster in forum 1996 - 2002 Z3 (E36/7, E36/8)
    Replies: 6
    Last Post: 07-07-2007, 10:30 PM
  5. Letting the cat out of the bag
    By 2000Z3M in forum 1996 - 2002 Z3 (E36/7, E36/8)
    Replies: 5
    Last Post: 06-22-2007, 08:26 AM

Bookmarks

Posting Permissions

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