Announcement

Collapse
No announcement yet.

Random shut-off problem

Collapse
X
Collapse
 
  • Page of 1
  • Filter
  • Time
  • Show
Clear All
new posts
Previous template Next
    #1

    Random shut-off problem

    My car's been M50 swapped for about 12,000 trouble-free miles, but then yesterday out of nowhere after a 200 mile trip it just shut off mid-drive.

    Wait thirty seconds or so and it'll fire right back up without issue and run perfectly, then die after about 30-45 seconds. Rinse and repeat.

    What's weird is that i'm not getting any codes, idle and power are perfect, and everything else seems normal. When it shuts off, i've still got electrical power, and the CEL stays on, which must mean the main relay is still fine.

    CPS is new (12,000 miles old, dropped it in at the start of my swap)
    Fuel pump relay replaced - same problem.
    Fuel pump primes when the key is turned to "on" after the car's been sitting for a few minutes
    It doesn't die like it's running out of fuel (no sputter or anything), but just like to pulled the key out. If the pump was dying, i'd get a sputter, right?

    Anyhow, i'm stumped at this point, and am just looking for any ideas!
    1988 Atlantisblau Euro/Japanese 325i Cabriolet
    1989 Schwartz 325i - now M50 powered! - now very dead
    1998 Toyota 4Runner Limited
    My 17,000km Big NA National Parks trip!
    Tags: None
    #2
    bump?
    I found this thread: http://www.r3vlimited.com/board/showthread.php?t=253479
    Has anyone had a problem with the sensor on the right for an NV M50?
    1988 Atlantisblau Euro/Japanese 325i Cabriolet
    1989 Schwartz 325i - now M50 powered! - now very dead
    1998 Toyota 4Runner Limited
    My 17,000km Big NA National Parks trip!

    Comment

      #3
      There's not many things that will keep the car from running. Most things just cause it to run like shit. The CPS is one I believe. Did you buy an OEM one or and off brand one? Try another DME maybe? Check power and grounds.

      Comment

        #4
        Hoping to revive an old thread as I am having the same issue. 1991 Non vanos m50 shuts off randomly while driving also after a 7 hour road trip. Thought it was cooking related and over time, replaced the whole cooling system to no avail. Lead to believe its a grounding issue now and further pursuing that. Any advice helps! Sent from my IN2017 using Tapatalk

        Comment

          #5
          Originally posted by bigolturbos22 View Post
          Hoping to revive an old thread as I am having the same issue. 1991 Non vanos m50 shuts off randomly while driving also after a 7 hour road trip. Thought it was cooking related and over time, replaced the whole cooling system to no avail. Lead to believe its a grounding issue now and further pursuing that. Any advice helps! Sent from my IN2017 using Tapatalk
          Hey mate,
          Check two things:
          1) Check your ground strap (engine, or engine mount arm to the body (usually on the left side if it's an M50 swap). If you're getting strange electrical behaviour before it cuts out, like a battery light, or flickering or anything, this strap can be replaced very cheaply and is good insurance.
          2) Replace your Crankshaft Position Sensor. This is what ended up being my problem. I had an aftermarket one, and even though it tested in-spec for resistance, it was still bad. Spring the $100 or so for a real BMW one from the dealer/online, it's worth the peace of mind.
          1988 Atlantisblau Euro/Japanese 325i Cabriolet
          1989 Schwartz 325i - now M50 powered! - now very dead
          1998 Toyota 4Runner Limited
          My 17,000km Big NA National Parks trip!

          Comment

            #6
            Originally posted by Sea Aych View Post

            Hey mate,
            Check two things:
            1) Check your ground strap (engine, or engine mount arm to the body (usually on the left side if it's an M50 swap). If you're getting strange electrical behaviour before it cuts out, like a battery light, or flickering or anything, this strap can be replaced very cheaply and is good insurance.
            2) Replace your Crankshaft Position Sensor. This is what ended up being my problem. I had an aftermarket one, and even though it tested in-spec for resistance, it was still bad. Spring the $100 or so for a real BMW one from the dealer/online, it's worth the peace of mind.
            1). Agreed.
            2). With a bad CPS (wires stripped and touching each other) my car ran, just not fantastically. This was on a single-VANOS M52 though, so ymmv

            Comment

              #7
              Originally posted by Sea Aych View Post
              Hey mate, Check two things: 1) Check your ground strap (engine, or engine mount arm to the body (usually on the left side if it's an M50 swap). If you're getting strange electrical behaviour before it cuts out, like a battery light, or flickering or anything, this strap can be replaced very cheaply and is good insurance. 2) Replace your Crankshaft Position Sensor. This is what ended up being my problem. I had an aftermarket one, and even though it tested in-spec for resistance, it was still bad. Spring the $100 or so for a real BMW one from the dealer/online, it's worth the peace of mind.
              Thank you for your help! Your advice has lead me to the most progress I've made in a while. I test drove it to the store after replacing the ground strap (engine to schassis) and crank sensor. She did great the whole time until I was pulling into my driveway then boom. Shuts off. I was totally sold on the crank sensor to fix this issue as the old one had some of the sheathing on the wire torn. Going to try the camshaft position sensor next and possibly a different ground. Could ECU also have a play in this? Cheers. Sent from my IN2017 using Tapatalk

              Comment

              Previous template Next
              Working...
              X