Results 1 to 6 of 6

Thread: '90 535i No Start - solved

  1. #1
    Join Date
    Aug 2009
    Location
    Sioux Falls, SD USA
    Posts
    291
    My Cars
    84 528e 88 735i, 01 325i

    '90 535i No Start - solved

    Yeah, I know this isn't an e32, but being a 535i, it's very, very similar to a 735i, and I feel like I know this forum far better than the e34 crowd, and am pretty sure an answer will come from here before I get one there!

    I've had this e34 since last fall; got it with zero maintenance history, but it was in decent shape and the price was right. Aside from a minor overheating issue that I resolved a month ago, it's been a great running & driving car. At least up until this weekend. I've been messing with it for way too long, so figured it's time to hit you all up for some better help.

    It ran fine driving to a meeting on Saturday morning, then on the way home I noticed the tach dropped to zero; engine died. What the heck? I coast to the next intersection and park it around the corner, and try the starter several times; nothing. No tools with me, so I couldn't do anything at the time, so I called my son to come drag me home. Moments after hanging up the phone I try the starter again, and it starts like nothing ever happened. Called him back to cancel, put it in drive, and started for home again. A block later it died again, but started again after a couple of starter bumps. In the ~2 miles to home it died two more times, both times deciding to start again after numerous tries. During those stops I also pulled the main and fuel pump relays to reseat them. Didn't seem to make any difference.

    I kinda suspected the fuel pump, so left it running when I got it into the driveway, then went to the trunk to listen for any strange noises. About that time the engine shut off again; the fuel pump stopped at about the same time, maybe a little later than the engine. It was like the ignition was shut off; it just quit. Weird. And since getting it home I've been unable to get it running at all.

    So it was an intermittent issue that seems to have become full-time. Here's where I am with troubleshooting so far.

    I jumpered the fuel pump relay, and the fuel pump runs, so that's not it. Wouldn't start with it jumpered either.

    Checked for spark; none.

    I jumpered the main relay and tried another known-good relay, no change.

    I had recently changed the spark plugs, wires, and dist cap. Getting nothing on all six made me think maybe it's the coil or coil wire, so first I swapped in the old coil wire; no change. Checked the voltage to the coil and got ~12V at terminal 15; normal. Resistance on the coil is normal, as is the coolant temp sensor.

    Any thoughts on where to start tracking things down? I have a copy of the ETM and a Bentley manual; I'll be pawing through those things this evening looking for anything that might help, but would greatly appreciate any advice you all might be able to offer.

    Thanks!

  2. #2
    Join Date
    Jan 2005
    Location
    Japan
    Posts
    54,655
    My Cars
    11/88 E32 750iL+98 E36M3
    Check the crankshaft position sensor
    Using digital multimeter, check resistance between terminals 1 and 2 in crankshaft position/rpm sensor connector.
    Crankshaft Position/rpm Sensor Specifications
    • Coil resistance (approx.) @ 20°C . . . . . . 540 ± 10% Ω
    • Air gap (sensor distance from
    toothed wheel) . . . . . . . 1.0 ± 0.3 mm (0.04 ± 0.01 in.)

    https://wiki.bentleypublishers.com/d...=1306522675840
    Shogun tricks and tips for the E32 series are HERE!

  3. #3
    Join Date
    Jul 2012
    Location
    South Yarmouth MA
    Posts
    550
    My Cars
    11/87 735i & 735il P/C
    It's a long shot, but I had a similar issue when I was getting my 735 running. I tried everything (including testing the crankshaft position sensor as @Shogun suggested) you did, but it ended up being a bad fuel pressure regulator. I got a new one on amazon for $25 and it immediately solved the random stalls and no-starts

    Note: it failed without any warning and my symptoms were nearly identical to yours
    Last edited by CamE32; 04-12-2018 at 04:01 PM.
    1983 4-spd Mercedes 240d w/403k - Sold!

    11/87 E32 735iA w/45k - Daily Driver (finally!)

    04/88 E32 735iL - Parts Car

  4. #4
    Join Date
    Jan 2005
    Location
    Japan
    Posts
    54,655
    My Cars
    11/88 E32 750iL+98 E36M3
    Looks like the CPS, here the replies for the same post on the E34 forum:
    shogun: Check the crankshaft position sensor
    ross1: This ^^ classic symptoms of this part failing.
    davintosh: Just checked the crankshaft position sensor; looks to be normal. Showed 0.5 on my DVM’s 200 ohm scale, but the temperature this morning is 10 degrees C. Position looks ok. I sprayed some cleaner on it and wiped away some grime. I don’t have a feeler gauge, but was able to slip a bit of cardboard in between that measures about 0.5mm, so it looks to be just under 1mm gap. Is there a way to check that sensor’s input at the DME, to confirm that the connections are ok?

    zubbie: Are you saying it reads 100 ohms then? If so then it's dead. Your symptoms mirror my experience when my CPS died. Care of Shogun. http://www.bimmerboard.com/forums/posts/645078

    fo3: They aren't reading it correct. Shogun says it should be 540 ohms and they are using a multimeter set for 200ohm range. Ohms readings of sensors is always a bit duff anyway - can confirm a fault but not really accurate enough to confirm a part is fine. You need working volts at least for that, or oscilloscope results; and all behavior points to CPS fault.

    davintosh: Doh. I was thinking that it was reading 500 ohms with the DVM on that setting, but in thinking about it that's not right; 500 ohms shouldn't be able to be read on the 200 ohm scale. With the DVM on the 2000 scale it reads zero, close to a short. If the sensor has failed, is it more common for the resistance to be too high or too low? Either way, I think I'll order a replacement.
    Shogun tricks and tips for the E32 series are HERE!

  5. #5
    Join Date
    Apr 2017
    Location
    San Diego, CA
    Posts
    232
    My Cars
    90' 735iL, 90' 535i, 93'
    +1 On that crank position sensor!
    I had the same issue last year, ended up buying a new fuel pump/filter/pressure regulator because it had first occurred with low fuel. I checked and replaced my fusible links and even drove an hour to get a junkyard DME. I really went on a wild goose chase.

    On the suggestion of a mechanic friend and shogun I finally changed the crank position sensor and all was restored to normal! The part is pretty inexpensive for a China version ($30ish) and was easy to replace on my 735. Heads up though! I was initially a bit confused trying to find the part because of the similarities to a Camshaft Position Sensor when searching the webs.

  6. #6
    Join Date
    Aug 2009
    Location
    Sioux Falls, SD USA
    Posts
    291
    My Cars
    84 528e 88 735i, 01 325i
    shogun and chazsandiego win the prize for this one; crankshaft position sensor! Many thanks, guys!

Similar Threads

  1. 1990 E34 535I "No Start"
    By JD1 in forum 1988 - 1996 (E34)
    Replies: 30
    Last Post: 10-13-2022, 09:08 AM
  2. s38b36 into e34 535i no start??
    By Natush in forum 1988 - 1996 (E34)
    Replies: 25
    Last Post: 03-26-2012, 03:40 AM
  3. early 06/90 535i no airbag aftermarket steering wheel
    By wyze in forum 1988 - 1996 (E34)
    Replies: 4
    Last Post: 03-08-2012, 01:08 AM
  4. Electrical Gremlins-No start Solved?
    By rllguitar in forum 1991 - 1999 (E36)
    Replies: 1
    Last Post: 09-22-2010, 01:12 AM
  5. Intermittent no start SOLVED
    By ChrisM011 in forum 1991 - 1999 (E36)
    Replies: 14
    Last Post: 04-08-2010, 03:59 PM

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
  •