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Thread: THE DEFINITIVE “NO START” trouble-shoot instructions

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    THE DEFINITIVE “NO START” trouble-shoot instructions

    In my own little adventure, I gathered a blend of info attained from various no-start threads and plain ol’ Bentley troubleshooting (member credits for thread info have been tagged when applicable. Apologies to anyone who feels slighted, but I don’t remember everywhere I read everything!). As I have an m60b30, there is a slight m60 lean to most topics, but hopefully the core info is still useful to most.


    * Many tests require a multi-meter. Most likely have them, but Noobs; if you own a car that is not under warranty or you own a home, you really should have one of these. They are $20-$30 and can be purchased from auto part stores, home improvement stores, and even Walmart. It’s not that complicated and it WILL save you time, frustration, and BIG MONEY in the long run. There is nothing worse than spending money to replace a part that wasn’t actually the problem.


    *Stomp tests or proper fault code readouts should be taken to save yourself some trouble when possible. If there is a “Check Engine Light”, then there is something stored that you should probably know about! (** if you have already tried to jumper your fuel pump, ignore the 1261 code! That was most likely tripped by the jumper, so don’t sweat it.)


    “THE” NO-START CAUSES (bold is most common)
    1. Fuel not reaching engine (empty tank?, bad fuel pump, injectors), Bentley section 160,130
    2. No Spark/voltage to plugs (Battery, plugs, coils, relays, wires/sensors), Bentley section 120
    3. Other (engine flooding, Air intake, and random things). Not particularly likely…but crazier things have happened!
    *the biggest no-brainer of all is if you get cranking, try jumpstarting your battery first to eliminate the prospect of a dead battery. Bring battery to auto parts store to test if still unsure. Once you know that’s not it, then proceed…


    -1. FUEL ISSUES:


    * Many fuel pump tests are made easier with a “jumper” in place of the relay (located in E box right side) so that engine cranking is not necessary in order to run pump. You can build a nice one that includes a fuse for roughly $9. At auto parts store, find spade terminal ends ($3), an “in-line fuse holder” (which includes wires already attached to fuse slot, $3) and then a pack of 15A fuses ($3). Crimp the ends onto the ready-made wire/fuse combo and you have instant and safe jumper. Jumper slots should correspond to terminal slots 30 & 87 from the Fuel Relay.


    *Access to fuel pump/sending unit is achieved by removing trunk carpet and unscrewing the obvious egg shaped panel (5 screws) on the right. The fuel sending unit really just measures ‘full/empty’, but it’s the middle man for power to the pump, so keep in mind the pump is under it. Removal of the pump is not necessary to check for voltage at the harness connections or even to test for pressure/flow. You only need to start pulling things apart if you decide to replace the pump.


    -Fuel pump fuse: Should ALWAYS be stop #1. The fuel pump fuse is #23 in the engine bay fuse box. If its blown, or looks even slightly off, try swapping it.

    -Check for power at the fuel pump. Details can be found in Bentley in section 160-6, but the gist of it is running the pump (via jumper) and listening if you can hear it and/or checking for voltage using your multi-meter (terminal 4/neg & 5/pos) at the harness connection. Power to the pump, but no pump activity when reconnected likely means shot pump (replace). If no power is supplied and/or jumpering the fuel relay doesn’t at least provide power, skip straight to trouble-shooting relays.


    - Check for pressure/flow (if pump has power, and activates)
    a. Pressure: Unhook the supply line IN at the RAIL in the engine bay and install a “T” with a fuel pressure gauge (nice kits are often available for rent at auto parts stores. They have expensive deposits, but you should get 100% of you money back upon return). Operate pump (via jumper) and check for around 51psi in M60/M50 and 44psi in M20/M30. Too high means blockages/kinks somewhere or the fuel pressure regulator is shot; too low means pump is shot or flow obstructed between pump and rail (clogged fuel filter most common culprit).


    * Despite easier access to sending unit/pump in trunk, all pressure/flow tests should be done in engine bay because pressure from the pump doesn’t necessarily tell you anything about gas actually reaching the injectors (ask me how I know!...)


    b. Flow: Disconnect RETURN line from fuel RAIL in engine bay and attach a length of hose to direct gas into a safe container from the rail. Operate pump with the jumper and you should get a nice stream filling approx a Quart in ~30 seconds. If you get a lot less, your pump may be shot (replace). “530IT” says he discovered during this test that a significant amount of what was pumping was actually water that somehow got into the tank, resulting in his no-start.


    *you may want to try and blow air through the return line, pressure regulator, and fuel filters. Clogs or kinks can def be a problem. Never use compressed air over 87psi though! It could cause damage to lines/parts.

    -Fuel Relay (locations vary): If the fuel pump gets power when you ‘jumper’ the terminal, but not when the relay alone is installed (and cranking with key), then its pretty clear the fuel relay needs to be replaced. If you get no power to pump either way, double check voltage to sockets with multi-meter, then see main relay.


    -Main Relay: If you can get one cheap, I say swap it right away. Bentley section 130-6 has details, but with ignition OFF, you need to pull it and check for voltage at terminals 30 & 86. If that’s fine, plug in the relay and turn ignition ON. Then you need to get access under it (accomplished via two 10mm bolts that allow the entire relay row to come up out of box, careful not to disconnect wires though). From the bottom, check for ground at the brown wire (terminal 31). If there is ground, you’re good, if not the ECM signal is missing. If fine, check voltage at both “87” terminals to see if the relay is “energized and functioning”. If Power is at fuel pump, and relays are looking good, then it could be an ignition system issue.



    -2. “Spark” IGNITION SYSTEMS:


    - Check for spark: Bentley outlines easier ways in other engines, but for my m60b30 I had to pull a coil, pull a plug, pop plug into coil (still-connected harness), and ground the plug to engine bay (I used a heavy copper wire that I first wrapped around the plug, then wrapped around the threaded stud, that normally secures coil. I bent the wire so that it held the coil/plug upright where it was easily visible from the driver seat), BUT BE CAREFUL. The shock could theoretically and LITERALLY KILL you). Crank the engine and if you see spark, then it’s not your coil, plugs, or starter. If you don’t see a spark…

    - Check Plugs and coils: Fouled plugs are hard to test, so I just bought new ones. Bentley section 120-4 outlines other engines, but the following info was, again, for an m60. For coil issues, first check for voltage to the coil connector harness (terminal 15/pos, ground/neg). IF no power, then you found your problem and trace back the wires to the fuses and/or relays. If voltage is present, test the coil itself for an ohm reading on your multi-meter. This really is more for if it runs like crap. As “Sir Montalbon” pointed out, the odds of 8 simultaneous failing coils leading to a no start is unlikely. Still, it only takes a few minutes and its best to be sure. Terminal 1/neg & 15/pos should give you of 0.4-0.8. Out of range = replace coil.


    - CHECK YOUR CPS!!!: The bad CPS (on front of engine, under air boot) is arguably the most common issue for no starts on m50 and m60 engines. Disconnect and test it’s resistance with your multi-meter (terminals 1 &2)

    Per ‘93FIM5’ “(if) This is reading below ~510-540 ohms I would say replace your CPS, that was my issue. The DME doesn’t see the engine cranking so it doesn’t initialize the pump or fire the plugs.”


    *the Bentley says a 1280 ohms +/-10% reading should be present in m60 and m50 engines, but the m50 CPS listing is generally acknowledge to be wrong. The 550 range is actually correct. People with m60s have claimed to have both 550ohms AND others claim 1250. It was reported by “dreiko” that Pelican parts told him the CPS itself has been superseded so many times that the originals may indeed have read 1280 and perhaps newer ones fall in line with 540ish. Considering the fact there are drastically differing styles, including ones with plastic vs. metal housings, this is not hard to imagine. In any case, most agree that a truly shot CPS will read an insane number (like ZERO or a number in the millions), so if you are in the neighborhood of either ‘spec’ number, you’re probably ok. If you’re stuck though, when in doubt- swap it out.


    -Check the injectors: Pop cover off the injector wiring ducts (tabs) and hook voltmeter to each injector. Pulsed voltage should be present 0.3-1.0 VDC while engaging starter. If not, check the red/white wire (pos) for voltage to the injectors.

    *Resistance of a pulled injector should be 10-20ohms (~16 @room temperature) on m50, m20, and m30 engines. M60 injector’s resistance is stated by the Bentley to be “not available from BMW”…



    3. OTHER (air intake, flooding, oddball/extreme occurrences):


    -A 50A fuse in the E-box: (US passenger side of engine bay) was the cause of “Sir Montalbon’s” no start issue. It seems to be a fuse relating to the air intake in some way. Someone else may clarify…


    -Engine Flooded: “sfgearhead” solved his problem by discovering he had flooded cylinders. He suggests pulling the plugs (only if you confirm you do have spark) and letting the cylinders breath and dry out. Crank the engine after pulling the fuel fuse to clear out trapped fuel. Be sure all components previously tested are back in place when attempting restart for real.


    *“mannd” elaborates with these excellent instructions: “The M60B30 motor, especially high mileage motors typically will have low compression. When they flood they can be nearly impossible to start, fuel saturates the intake and engine oil. When you first pulled out the spark plugs, are they wet? If they are and seeing that you have spark, try the following..........”


    1. Remove and dry out all spark plugs
    2. With spark plugs out and DME relay removed crank over motor to evacuate cylinders.
    3. Refit plugs and DME relay
    4. Remove fuel pump fuse
    **Get a second person to help with the following. Ensure battery is charged fully and use a good battery charger as this process will be taxing on the starter and battery**
    5. With the accelerator to the floor at all times, start cranking motor until started then ease off (this is clear flood mode).
    6. When you hear the engine trying to start have the second person momentarily fit the fuse and remove.
    7. Continue this process until the engine starts.


    -MAF: A dirty or faulty MAF may cause some problems. Check for voltage with multi-meter. The problem here, as I see it, is the Bentley says a faulty MAF “usually” will still let the engine “start and run” (it just runs like crap). A full blown non-start is, in my opinion, unlikely to be caused by the MAF. But hey, if you’re out of ideas or if you discover you’re not getting power to the MAF at all, def trace back the wires/fuses for issues and/or try swapping it.


    -Air Filter: Super blocked/clogged one would def prevent strong running, and possibly choke out an engine. Check it for buildup, clean/replace it and give her another go.


    -The DME: 93FIM5 reports you need a pin-out of the DME to accomplish anything. I am clueless on this topic. If anyone can chime in that would be great.


    -The EWS II (security system) can possibly disable a starter. For more info on that see Porschedude’s informative thread http://forums.bimmerforums.com/forum...ws+porschedude
    “KyleCleveland” suggests trying alternate key. If the EWS isn’t getting the “it’s all good” signal from a faulty main key, perhaps the backup key is still intact. Always worth a shot.


    - The starter. I have no experience here, but I suspect this should only be a suspicion of your truly getting zippy for output/cranking/power. If its trying to crank, it shouldn’t be the starter.


    -Blown Motor. Do a compression test and find out. I suggest you do the compression test while doing the “evacuate” process of trouble shooting the flooded engine. You will already have the plugs out and DME & Fuel relays unhooked, so you may as well slap a compression gauge in there and see what’s up while you’re at it. Harbor freight sells the gauges cheap.


    -Incorrect valve timing. Particularly older engines. Very eloborate process, see Bentley sec. 116




    To those reading this for fun, please share your own stories about problems AND SOLUTIONS to your no-start issue (ESPECIALLY if not already covered)!.

    To those reading out of necessity, best of luck!!!
    Last edited by BigBisonT; 03-04-2011 at 02:20 PM. Reason: Spacing is/was all out of whack
    "I have come here to chew bubbleguma and kick @ss...and im all outta bubblegum" -Rowdy Roddy Piper

  2. #2
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    printing!, nice

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    Nice. Very nice.

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    Wow, very informative. My 540i has never not started, but it is great to have this info. Good job!

  6. #6
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    For the DIY.

    8 more submissions and a divorce and you win a free car!

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    Quote Originally Posted by zubbie View Post
    For the DIY.

    8 more submissions and a divorce and you win a free car!
    That should be the official BF.C E34 promotion.

  8. #8
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    Quote Originally Posted by zubbie View Post
    For the DIY.

    8 more submissions and a divorce and you win a free car!
    too soon?
    Own:
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  9. #9
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    Quote Originally Posted by HlyDvlz1989 View Post
    too soon?
    perhaps...bit I'm generally pushing the envelope

  10. #10
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    The crank position sensor is a fairly common issue on the M30 as well. It was the missing piece in my car's no-start
    (OO=00=OO)

  11. #11
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    Yeah, too soon.....

    Awesome info, needs more pics !!

  12. #12
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    just a little bump because ive seen like 4 "no start" threads in the last week and all of them say "i searched but..."

    I swear I dont want to be a douche yelling "look at me and what I did!!", but come on guys. I know a lot of the steps are tedius and require effort, but anyone claiming this had no useful info is just being lazy.

    You guys who have hit a wall, i feel your pain. In my 'wits' end thread, i went nearly 2 months without my car for no-start. Turns out I flooded it, incorrectly diagnosed it as fuel pump and replaced it (with a used one that turned out to be bad itself), incorrectly determined the bad fuel pump was good by pressure testing it at the pump (instead of the rail) and it wasnt until I put the original pump back in and did the flood clearing procedure that I was up and running again. It sucks, but its a process that requires patience and WORK. No one can gift wrap this for you. Do the steps and, unlike me the first time, do them correctly!
    "I have come here to chew bubbleguma and kick @ss...and im all outta bubblegum" -Rowdy Roddy Piper

  13. #13
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    Thank you.. now this is what i am looking for. there is nothing on the web like this, also i guess im going to have to get a bentley book.... lol but i am also printing this out

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    bump this needs to be put into the DIY section

  15. #15
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    Quote Originally Posted by zubbie View Post
    For the DIY.

    8 more submissions and a divorce and you win a free car!


    Good write up BigBison

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    Went out to my '95 525it two days ago after it sat for about 24 hours to find out it wouldn't start. First time I've ever had a car that didn't start. The fuel pump has been making a lot of noise lately, so I initially assumed it was the culprit. Cranks over fine, but it wouldn't fire. Jumped what I *thought* was the fuel pump relay (Thanks Bently Manual!) and the pump didn't turn on, so I replaced it. Still won't start. The pump won't even turn on when I turn the key. Pump turns on when I jump a different (actual fuel pump) relay. Searching for other options brought me to here. Tonight I will be going through the list and hopefully finding the culprit.
    The CPS intrigues me since the tach doesn't register anything while I'm turning the engine over. Does the tach normally show RPM's while starting? I've never really noticed. Thanks to the OP for posting this! I'll update with my findings.

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    Mine didn't start at 5:30 this morning... but it was for the oddest reason.

    When I go to unlock my driver's door, it was already unlocked... but all the others were locked. I try to start it and get no crank. So I pull to unlock the passenger door and get all the doors unlocked. I then try it and it starts no problem... stupid computer playing games with me early in the morning :P

  18. #18
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    CPS tested out to be 504 ohms. What do you think? Replace or not?

    Well, I decided to replace the CPS. I did and it still wouldn't start. I pulled the plugs out again and found it to be flooded. I followed the procedure above and eventually got it running. I have no idea what the exact problem was and I don't know when it got flooded, but I replaced the fuel pump, CPS and evacuated the cylinders and it now it starts.
    Last edited by JSavela; 11-05-2011 at 06:15 PM. Reason: Update

  19. #19
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    Thank you for this.

    Thank you for this -

    I have 1994 530i that has had a couple issues as of late.

    Ran rough once and died - Replaced MAF and ran fine for 6 months. Had a no start issue a while back, couldn't figure it out - Lambda II OBD code - replaced the 02 sensors, didn't fix it , dragged it to a shop to find out it was a weak fuel pump. Replaced it (and the pair of parallel fuel filters) and ran fine. Replaced leaky valve cover gaskets

    Now 3 months later my daughter is driving it and it dies . .. Cranks but no start. No OBD codes . . .

    Anyway, I went through the list via threads, Bentley Manuals and knew the fuel pump wasn't running at all. Bought a replacement fuel pump before testing power at the pump (poor problem solving) and then realized no power at the pump (tested per Bentley manual)

    • Checked Fuse 23
    • Jumped Fuel Pump Relay (I've been jumping the wrong one)
    • tested power at fuel pump - no power - "hot wired" the pump and it runs
    • tested resistance at Crank Position Sensor (~500 ohms so OK)
    • tested cam sensor (~1000 ohms so OK)
    • looked under car for broken wires


    Now - looking at the photo and description of the relays in the E Box provided by govee (this is the first photo that looks like mine) - I think I have been testing the O2 relay, and not the fuel pump relay.

    Going to try tonight to jump the fuel pump relay and see what happens. I'm just wondering if I can swap the O2 relay with the Fuel Pump relay. I'd jump the fuel pump relay, but the one installed isn't labeled on the underside with 30, 85, 86, 87. Maybe I'll jump the same position as if it was the same relay, and see what happens.

    Lots of good stuff.

    Thank you


    Quote Originally Posted by BigBisonT View Post
    In my own little adventure, I gathered a blend of info attained from various no-start threads and plain ol’ Bentley troubleshooting (member credits for thread info have been tagged when applicable. Apologies to anyone who feels slighted, but I don’t remember everywhere I read everything!). As I have an m60b30, there is a slight m60 lean to most topics, but hopefully the core info is still useful to most.


    * Many tests require a multi-meter. Most likely have them, but Noobs; if you own a car that is not under warranty or you own a home, you really should have one of these. They are $20-$30 and can be purchased from auto part stores, home improvement stores, and even Walmart. It’s not that complicated and it WILL save you time, frustration, and BIG MONEY in the long run. There is nothing worse than spending money to replace a part that wasn’t actually the problem.


    *Stomp tests or proper fault code readouts should be taken to save yourself some trouble when possible. If there is a “Check Engine Light”, then there is something stored that you should probably know about! (** if you have already tried to jumper your fuel pump, ignore the 1261 code! That was most likely tripped by the jumper, so don’t sweat it.)


    “THE” NO-START CAUSES (bold is most common)
    1. Fuel not reaching engine (empty tank?, bad fuel pump, injectors), Bentley section 160,130
    2. No Spark/voltage to plugs (Battery, plugs, coils, relays, wires/sensors), Bentley section 120
    3. Other (engine flooding, Air intake, and random things). Not particularly likely…but crazier things have happened!
    *the biggest no-brainer of all is if you get cranking, try jumpstarting your battery first to eliminate the prospect of a dead battery. Bring battery to auto parts store to test if still unsure. Once you know that’s not it, then proceed…


    -1. FUEL ISSUES:


    * Many fuel pump tests are made easier with a “jumper” in place of the relay (located in E box right side) so that engine cranking is not necessary in order to run pump. You can build a nice one that includes a fuse for roughly $9. At auto parts store, find spade terminal ends ($3), an “in-line fuse holder” (which includes wires already attached to fuse slot, $3) and then a pack of 15A fuses ($3). Crimp the ends onto the ready-made wire/fuse combo and you have instant and safe jumper. Jumper slots should correspond to terminal slots 30 & 87 from the Fuel Relay.


    *Access to fuel pump/sending unit is achieved by removing trunk carpet and unscrewing the obvious egg shaped panel (5 screws) on the right. The fuel sending unit really just measures ‘full/empty’, but it’s the middle man for power to the pump, so keep in mind the pump is under it. Removal of the pump is not necessary to check for voltage at the harness connections or even to test for pressure/flow. You only need to start pulling things apart if you decide to replace the pump.


    -Fuel pump fuse: Should ALWAYS be stop #1. The fuel pump fuse is #23 in the engine bay fuse box. If its blown, or looks even slightly off, try swapping it.

    -Check for power at the fuel pump. Details can be found in Bentley in section 160-6, but the gist of it is running the pump (via jumper) and listening if you can hear it and/or checking for voltage using your multi-meter (terminal 4/neg & 5/pos) at the harness connection. Power to the pump, but no pump activity when reconnected likely means shot pump (replace). If no power is supplied and/or jumpering the fuel relay doesn’t at least provide power, skip straight to trouble-shooting relays.


    - Check for pressure/flow (if pump has power, and activates)
    a. Pressure: Unhook the supply line IN at the RAIL in the engine bay and install a “T” with a fuel pressure gauge (nice kits are often available for rent at auto parts stores. They have expensive deposits, but you should get 100% of you money back upon return). Operate pump (via jumper) and check for around 51psi in M60/M50 and 44psi in M20/M30. Too high means blockages/kinks somewhere or the fuel pressure regulator is shot; too low means pump is shot or flow obstructed between pump and rail (clogged fuel filter most common culprit).


    * Despite easier access to sending unit/pump in trunk, all pressure/flow tests should be done in engine bay because pressure from the pump doesn’t necessarily tell you anything about gas actually reaching the injectors (ask me how I know!...)


    b. Flow: Disconnect RETURN line from fuel RAIL in engine bay and attach a length of hose to direct gas into a safe container from the rail. Operate pump with the jumper and you should get a nice stream filling approx a Quart in ~30 seconds. If you get a lot less, your pump may be shot (replace). “530IT” says he discovered during this test that a significant amount of what was pumping was actually water that somehow got into the tank, resulting in his no-start.


    *you may want to try and blow air through the return line, pressure regulator, and fuel filters. Clogs or kinks can def be a problem. Never use compressed air over 87psi though! It could cause damage to lines/parts.

    -Fuel Relay (locations vary): If the fuel pump gets power when you ‘jumper’ the terminal, but not when the relay alone is installed (and cranking with key), then its pretty clear the fuel relay needs to be replaced. If you get no power to pump either way, double check voltage to sockets with multi-meter, then see main relay.


    -Main Relay: If you can get one cheap, I say swap it right away. Bentley section 130-6 has details, but with ignition OFF, you need to pull it and check for voltage at terminals 30 & 86. If that’s fine, plug in the relay and turn ignition ON. Then you need to get access under it (accomplished via two 10mm bolts that allow the entire relay row to come up out of box, careful not to disconnect wires though). From the bottom, check for ground at the brown wire (terminal 31). If there is ground, you’re good, if not the ECM signal is missing. If fine, check voltage at both “87” terminals to see if the relay is “energized and functioning”. If Power is at fuel pump, and relays are looking good, then it could be an ignition system issue.



    -2. “Spark” IGNITION SYSTEMS:


    - Check for spark: Bentley outlines easier ways in other engines, but for my m60b30 I had to pull a coil, pull a plug, pop plug into coil (still-connected harness), and ground the plug to engine bay (I used a heavy copper wire that I first wrapped around the plug, then wrapped around the threaded stud, that normally secures coil. I bent the wire so that it held the coil/plug upright where it was easily visible from the driver seat), BUT BE CAREFUL. The shock could theoretically and LITERALLY KILL you). Crank the engine and if you see spark, then it’s not your coil, plugs, or starter. If you don’t see a spark…

    - Check Plugs and coils: Fouled plugs are hard to test, so I just bought new ones. Bentley section 120-4 outlines other engines, but the following info was, again, for an m60. For coil issues, first check for voltage to the coil connector harness (terminal 15/pos, ground/neg). IF no power, then you found your problem and trace back the wires to the fuses and/or relays. If voltage is present, test the coil itself for an ohm reading on your multi-meter. This really is more for if it runs like crap. As “Sir Montalbon” pointed out, the odds of 8 simultaneous failing coils leading to a no start is unlikely. Still, it only takes a few minutes and its best to be sure. Terminal 1/neg & 15/pos should give you of 0.4-0.8. Out of range = replace coil.


    - CHECK YOUR CPS!!!: The bad CPS (on front of engine, under air boot) is arguably the most common issue for no starts on m50 and m60 engines. Disconnect and test it’s resistance with your multi-meter (terminals 1 &2)

    Per ‘93FIM5’ “(if) This is reading below ~510-540 ohms I would say replace your CPS, that was my issue. The DME doesn’t see the engine cranking so it doesn’t initialize the pump or fire the plugs.”


    *the Bentley says a 1280 ohms +/-10% reading should be present in m60 and m50 engines, but the m50 CPS listing is generally acknowledge to be wrong. The 550 range is actually correct. People with m60s have claimed to have both 550ohms AND others claim 1250. It was reported by “dreiko” that Pelican parts told him the CPS itself has been superseded so many times that the originals may indeed have read 1280 and perhaps newer ones fall in line with 540ish. Considering the fact there are drastically differing styles, including ones with plastic vs. metal housings, this is not hard to imagine. In any case, most agree that a truly shot CPS will read an insane number (like ZERO or a number in the millions), so if you are in the neighborhood of either ‘spec’ number, you’re probably ok. If you’re stuck though, when in doubt- swap it out.


    -Check the injectors: Pop cover off the injector wiring ducts (tabs) and hook voltmeter to each injector. Pulsed voltage should be present 0.3-1.0 VDC while engaging starter. If not, check the red/white wire (pos) for voltage to the injectors.

    *Resistance of a pulled injector should be 10-20ohms (~16 @room temperature) on m50, m20, and m30 engines. M60 injector’s resistance is stated by the Bentley to be “not available from BMW”…



    3. OTHER (air intake, flooding, oddball/extreme occurrences):


    -A 50A fuse in the E-box: (US passenger side of engine bay) was the cause of “Sir Montalbon’s” no start issue. It seems to be a fuse relating to the air intake in some way. Someone else may clarify…


    -Engine Flooded: “sfgearhead” solved his problem by discovering he had flooded cylinders. He suggests pulling the plugs (only if you confirm you do have spark) and letting the cylinders breath and dry out. Crank the engine after pulling the fuel fuse to clear out trapped fuel. Be sure all components previously tested are back in place when attempting restart for real.


    *“mannd” elaborates with these excellent instructions: “The M60B30 motor, especially high mileage motors typically will have low compression. When they flood they can be nearly impossible to start, fuel saturates the intake and engine oil. When you first pulled out the spark plugs, are they wet? If they are and seeing that you have spark, try the following..........”


    1. Remove and dry out all spark plugs
    2. With spark plugs out and DME relay removed crank over motor to evacuate cylinders.
    3. Refit plugs and DME relay
    4. Remove fuel pump fuse
    **Get a second person to help with the following. Ensure battery is charged fully and use a good battery charger as this process will be taxing on the starter and battery**
    5. With the accelerator to the floor at all times, start cranking motor until started then ease off (this is clear flood mode).
    6. When you hear the engine trying to start have the second person momentarily fit the fuse and remove.
    7. Continue this process until the engine starts.


    -MAF: A dirty or faulty MAF may cause some problems. Check for voltage with multi-meter. The problem here, as I see it, is the Bentley says a faulty MAF “usually” will still let the engine “start and run” (it just runs like crap). A full blown non-start is, in my opinion, unlikely to be caused by the MAF. But hey, if you’re out of ideas or if you discover you’re not getting power to the MAF at all, def trace back the wires/fuses for issues and/or try swapping it.


    -Air Filter: Super blocked/clogged one would def prevent strong running, and possibly choke out an engine. Check it for buildup, clean/replace it and give her another go.


    -The DME: 93FIM5 reports you need a pin-out of the DME to accomplish anything. I am clueless on this topic. If anyone can chime in that would be great.


    -The EWS II (security system) can possibly disable a starter. For more info on that see Porschedude’s informative thread http://forums.bimmerforums.com/forum...ws+porschedude
    “KyleCleveland” suggests trying alternate key. If the EWS isn’t getting the “it’s all good” signal from a faulty main key, perhaps the backup key is still intact. Always worth a shot.


    - The starter. I have no experience here, but I suspect this should only be a suspicion of your truly getting zippy for output/cranking/power. If its trying to crank, it shouldn’t be the starter.


    -Blown Motor. Do a compression test and find out. I suggest you do the compression test while doing the “evacuate” process of trouble shooting the flooded engine. You will already have the plugs out and DME & Fuel relays unhooked, so you may as well slap a compression gauge in there and see what’s up while you’re at it. Harbor freight sells the gauges cheap.


    -Incorrect valve timing. Particularly older engines. Very eloborate process, see Bentley sec. 116




    To those reading this for fun, please share your own stories about problems AND SOLUTIONS to your no-start issue (ESPECIALLY if not already covered)!.

    To those reading out of necessity, best of luck!!!
    Last edited by dwkestell; 09-14-2018 at 09:39 AM.

  20. #20
    Join Date
    Dec 2008
    Location
    Ninety Six, SC
    Posts
    1
    My Cars
    '92 525i
    92 e34 525i 147k miles I am 2nd owner. Had the car for a year no problems. Today I go to start the car and it cranks and cranks but will not run. Not getting fuel. Changed fuel pump with other identical 525 and nothing. Relay swap nothing. Jumper pins in socket and run gas into container under hood no problem. Connected LED test light to coil pins is socket and when I turn key to start I see light blink once as engine cranks. Any help appreciated.

  21. #21
    Join Date
    May 2017
    Location
    Perth, Western Australia
    Posts
    1,101
    My Cars
    09/90 E34 525i (M50)
    Most likely crank position sensor as mentioned above, eg:
    Quote Originally Posted by BigBisonT View Post
    I

    - CHECK YOUR CPS!!!: The bad CPS (on front of engine, under air boot) is arguably the most common issue for no starts on m50 and m60 engines. Disconnect and test it’s resistance with your multi-meter (terminals 1 &2)

    Per ‘93FIM5’ “(if) This is reading below ~510-540 ohms I would say replace your CPS, that was my issue. The DME doesn’t see the engine cranking so it doesn’t initialize the pump or fire the plugs.”


    *the Bentley says a 1280 ohms +/-10% reading should be present in m60 and m50 engines, but the m50 CPS listing is generally acknowledge to be wrong. The 550 range is actually correct. People with m60s have claimed to have both 550ohms AND others claim 1250. It was reported by “dreiko” that Pelican parts told him the CPS itself has been superseded so many times that the originals may indeed have read 1280 and perhaps newer ones fall in line with 540ish. Considering the fact there are drastically differing styles, including ones with plastic vs. metal housings, this is not hard to imagine. In any case, most agree that a truly shot CPS will read an insane number (like ZERO or a number in the millions), so if you are in the neighborhood of either ‘spec’ number, you’re probably ok. If you’re stuck though, when in doubt- swap it out.

  22. #22
    Join Date
    May 2010
    Location
    Honolulu, Hawaii
    Posts
    753
    My Cars
    '73 E9, '94 E34, '02 E46
    itafta: you need to provide a little more info, edit your original post. Also, test sequence can be important.

    #1 How did you determine it wasn't getting fuel, this may be significant. When my E46 wouldn't start, I sprayed to gas into the intake and it would start immediately and run only a few seconds before dying. That is a definitive "no gas" test. But you jumped the relay and got gas, so your pump is good.

    #2 Changing the fuel pump when you get a "no gas" situation ignores that the fuel filter on older bimmers often clogs. Then the pump from heaven can't push fuel, or enough fuel, for the engine to run. I'd first take off the fuel filter, drain it and try blow through it. One can blow through a clean dry filter easily; a wet filter with very little resistance; a clogged filter not at all. But you jumped the relay and got gas, so your pump is good.

    #3 Your LED test light appears to tell you there is spark only once, thus your problem appears to be in the ignition. Suggest use the voltmeter to check the crank position sensor. They can go intermittently bad (I hate intermittent problems). Make sure it is correctly positioned or it won't trigger, telling the ECU that the engine is turning over and needs spark.
    Charlie

    Your mission, should you decide to accept it, is to add value to these threads, either by pictures or by descriptions, so the next person with the same or similar problem stands on your shoulders.

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