Reply to Thread

Post a reply to the thread: Odd bucking and power drop

Your Message

Click here to log in

Please correctly re-type the phrase f o o t d o c t o r in the form box. Re-type it without the extra spaces and put the one space where it should be. We apologize for having to do this but this silliness helps slow the spammers.


Additional Options

Topic Review (Newest First)

  • 03-29-2011, 03:58 PM

    You can say that again!

    Won't even let you post just a title line...I just found out
  • 03-29-2011, 06:35 AM
    In frustration of continued problems coupled with the need to be in traffic court ,I towed my 6er into my new friends at Black Forest BMW . They determined the wiring to the Main & Fuel Pump relays to be the culprit.The Dragon Shark now drives like a dream..I think the problems are fallout from POs aftermarket alarm that still has me without central locking and interior lights that must be turned off manually.

    PS Im not diggin' this new format. The old setup let you see a conversation in a glance. The new makes you trudge through Betty is hidden
  • 02-24-2011, 06:35 PM

    No need to tell you to check the battery cables...

    right? You are too astute to forget I did (Doh!) Yep got her up and running like a champ but got the occasionalpower drop etc.. Found I'd left the cable loose just for testing LOL.
  • 02-17-2011, 05:08 AM

    Check alternator charging and relays for tach

    Issues. The ignition and ecu systems need steady current to fire the plugs and injectors.
    There is also an ignition switch (steering column) that wears out and needs higher voltage to throw the combination relay in the start circuit. There is a bypass in the big round trouble shooting diagnostic connector next to the fuse box. What is that thing called? When my ignition switch doesn't get it, I turn the key on and start it from under the hood. But that's when I ' m running the AC and about half of my stereo. I've gotten a 140amp alternator, its just waiting for the engine to be put c
    3.9L Stage 4
    Suspension Stage 3
    Glass Euro Widebody Shaved
    17X12 Forged HRE's
    1kw RMS X 17 drivers
  • 02-15-2011, 06:48 AM

    Re: Doubt lack of back pressure

    Went out for a drive and the intermittent bucking became more & more prevalent. Seems if I kept the rpm high and constant it would be all right. Backing off the gas pedal sent the tach needle to zero then twitching like a Geiger counter before lots of revs would calm it back down.

    Headed over to the local Junkyard.BTW PickApart in Ontario Calif. is a must-check-out for those in SoCal.Vast & sprawling, a huge German Section, vintage section including 60s Detroit iron, old MGs , a W108 Benz,oddballs like a Hillman Minx & more all with a view of snow-capped mountains.

    Once there I tracked down and pulled the 6th plug wire with pick-up wire for the sensor off an E32 735i. Put it on but.....Its BAAAAACK the dreaded bucking so bad that I pulled off the freeway twice before I had a no start condition. After waiting nearly 2 hours for a tow she fired up & I made it the last 10 miles home. Hope the new brain isn't fried.<b><I>SirTweakAlot</i></b>

    88 635CSi 5speed

    64 1/2 Mustang Convt.,

    03 Triumph Daytona/Speed Triple

    85 u.s. 635CSi,
    84 euro 635CSi,
    83 u.s. 633CSi

  • 02-14-2011, 12:09 PM

    Doubt lack of back pressure

    My M6 does not do that whatsoever and I have no cats as well. I would check the TPS with a meter to see if it is at fault. Simple procedure to test.
  • 02-12-2011, 02:55 PM

    Re: Odd bucking and power drop DECELERATION ISSUE!

    Recently if I am driving in 3rd or 4th at about 70 + MPH and I take my foot off the gas pedal as the car begins to slow down it " bucks " or has a mild " jerk " my best description is that it seems to be " gasping for air " It should just slown down on its own from the reduction of gas to the motor. Several people on other forums have said maybe its the throttle position switch or sensor. Others have said its the AHM ? Still do not know what it is. My mechanic who has not driven the car says that it may be due to lack of back pressure as I do not have the catalytic converters on my 55 k mile 88 M6.
  • 02-12-2011, 03:36 AM

    Odd bucking and power drop

    I finally got Dragon Shark back on the road after weeks of permanent residency at Rick's No Start. Turned out to be the ECU.

    Now I'm plagued by intermittent odd hesitation and rev drops while driving

    Some likely suspects- in my search for the answer to no-start , a couple of the 23 year old connectors crumbled in my hands...replaced by copious amounts of electrical tape.One of these was on the airbag circuit- I have not put the airbag back in & now I'm a bit leery of doing so

    I also snapped the wire off the ring that goes round 6th plug wire. Not exactly sure what it does. I think these are only on later 6ers.This lil plastic ring on a wire goes for $70 new.I was hoping to find one at the junkyard.What other BMWs to look in? E32 and E34?

    Anything else that might cause this?

    88 635CSi 5speed

    64 1/2 Mustang Convt.,

    03 Triumph Daytona/Speed Triple

    85 u.s. 635CSi,
    84 euro 635CSi,
    83 u.s. 633CSi

Posting Permissions

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
1e2 Forum