Captain Beaky Posted September 11, 2022 Share Posted September 11, 2022 Went to pop down to the West Wales BMW club coffee & Car weekly meet and nothing the car just turned over. and would not start. Its the M535i no previous signs of the impending failure, it just wont start after parking it in the garage last week. I cannot here the fuel pump start on ignition the normal prime, it does work when bridging the relay, tank is full Won't fire even if I spray ether or petrol into the inlet boot so no spark! Injectors have power with the ignition on, also the air idle valve fires up and I can here it working Swapped both DME and Fuel pump really as a matter of course. Ive checked all the earth connections and they are fine So no spark and the fuel pump won't start, I'm thinking DME Any suggestions I can't see it being the crankshaft sensor or the position sensor on the bell housing because that control circuit should not stop the pump prime on ignition I'm I having a blonde moment here🙄 Quote Link to comment Share on other sites More sharing options...
Sharkfan Posted September 11, 2022 Share Posted September 11, 2022 Check the crankshaft position sensors near the back of the engine - it'll be one of them. There is the correct info on this thread on how to test the speed and reference sensors (which are identical but do different jobs for the ECU) https://bigcoupe.com/phpBB2/viewtopic.php?p=214705&hilit=reference+sensor+resistance#p214705 Quote Link to comment Share on other sites More sharing options...
Captain Beaky Posted September 11, 2022 Author Share Posted September 11, 2022 Yes, I think you are right, that's where I was heading. I just put the lamp back on the injector plug and it does not pulse when I Turn the engine over the lamp just stays on. What I can't believe is that last week it was fine, I park it up for several days and failure!! REALLY?? not what I wanted today Quote Link to comment Share on other sites More sharing options...
JohnH Posted September 12, 2022 Share Posted September 12, 2022 Motronic wont turn the fuel pump on till engine turning over at 400rpm or more. Reversed mine out the garage and it stalled halfway out. Fuel pump dead as a dodo. Full of crud. I was going for an MOT next day. Really fed up. Quote Link to comment Share on other sites More sharing options...
duncan-uk Posted September 12, 2022 Share Posted September 12, 2022 DME and fuel pump are different types of relay so swapping won't help but you can jury rig it to by pass. If only someone had written a no start guide.... Oh hang on! Quote Link to comment Share on other sites More sharing options...
Captain Beaky Posted September 12, 2022 Author Share Posted September 12, 2022 4 hours ago, duncan-uk said: DME and fuel pump are different types of relay so swapping won't help but you can jury rig it to by pass. If only someone had written a no start guide.... Oh hang on! Hey Duncan its been a while👊 I swapped the relays out for spares give me some credit 😂😂 I did use a jumper to bypass the fuel relay and the pump works fine but for some reason I was convinced that as soon as the ignition was switched on the pump gave a short bust to prime, however I was a little apprehensive in bypassing the DME relay. Can you tell me do you know what is the trigger on a manual for the bell housing position sensors? I had a similar issue on the Donkey but that's a 525e auto and the tang sticking out came off the torque converter plate and so I lost the reference point. Is it the same for a manual or is it a plate spot welded to the flywheel Quote Link to comment Share on other sites More sharing options...
Captain Beaky Posted September 12, 2022 Author Share Posted September 12, 2022 10 hours ago, JohnH said: Motronic wont turn the fuel pump on till engine turning over at 400rpm or more. Reversed mine out the garage and it stalled halfway out. Fuel pump dead as a dodo. Full of crud. I was going for an MOT next day. Really fed up. Bugger, So you had better check your fuel tank for crap! as well as sorting the pump Quote Link to comment Share on other sites More sharing options...
Sharkfan Posted September 12, 2022 Share Posted September 12, 2022 Fuel tanks are generally clean but the foot shaped gauze at the bottom of the sender can wax up so that's worth a quick look (boot floor, a few screws, no naked lights etc) - as well as changing the fuel filter by the pump of course. Fuel supply problems (other than outright fuel pump failure) generally manifest as limited stumbling revs under load and latterly refusal to rev at all. 19 hours ago, Captain Beaky said: Yes, I think you are right, that's where I was heading. I just put the lamp back on the injector plug and it does not pulse when I Turn the engine over the lamp just stays on. What I can't believe is that last week it was fine, I park it up for several days and failure!! REALLY?? not what I wanted today Motronic sensors work well until they don't - that said - I've suffered intermittent failure as well as sudden immediate failure - get the ohmmeter out and check. Quote Link to comment Share on other sites More sharing options...
Captain Beaky Posted September 12, 2022 Author Share Posted September 12, 2022 Well its confirmed ive got a dead sensor over 10 M ohms no matter what pins and the other is bang on 992. So as we'd say in Wales " Mae wedi ffycin torri" It has fuc*ing broken, that's for you boys over the border id better start trawling through the spares☹️ Quote Link to comment Share on other sites More sharing options...
Captain Beaky Posted September 12, 2022 Author Share Posted September 12, 2022 Okay should there be a cover over the sensors?? Quote Link to comment Share on other sites More sharing options...
JohnH Posted September 13, 2022 Share Posted September 13, 2022 Bowel Reinforcement seems to be missing. #15 in this pic http://bmwfans.info/parts-catalog/E28/Europe/M535i-M30/browse/engine/engine_block/ Quote Link to comment Share on other sites More sharing options...
duncan-uk Posted September 13, 2022 Share Posted September 13, 2022 Sorry beaky - i just read it as swapped over not replaced but someone reading in the future might benefit from knowing they are not the same Now if i remember you can use a landrover part to replace these which are good value. I answer to the earlier question i think its a pin on the flywheel that activates the sensors - it has been known for these to drop off. Quote Link to comment Share on other sites More sharing options...
Captain Beaky Posted September 13, 2022 Author Share Posted September 13, 2022 Hey Dunc just jesting i realized when i read it back it could be both ways😆 Anyway sensor is at the motor factors ready to be picked up, £60 but Bosch so not too bad Quote Link to comment Share on other sites More sharing options...
duncan-uk Posted September 13, 2022 Share Posted September 13, 2022 Yes i know 👍 But of course if hadn't said and you had just swapped them that woulkd be no help either. Better to state obvious i feel. Awaiting to hear of sucess! Quote Link to comment Share on other sites More sharing options...
Captain Beaky Posted September 14, 2022 Author Share Posted September 14, 2022 Right guys these position sensors, Ive never ever managed to get on out whole in the past but these two have only been in there about 6 years better than 20. Does anyone have some super tip to extract them? Quote Link to comment Share on other sites More sharing options...
Sharkfan Posted September 14, 2022 Share Posted September 14, 2022 Undo the bolt and hope they wiggle straight out - I had one on my 635CSi and my M635CSi do exactly that. I also had one on my 635CSi refuse to move so resorted to all kinds of sprays, levers, pullers and everything to get it out - fortunately my 635CSi is an automatic so I took the flywheel coverplate off and ended up pushing it out from the inside - god knows what you do with a manual... Quote Link to comment Share on other sites More sharing options...
Captain Beaky Posted September 14, 2022 Author Share Posted September 14, 2022 These are not wiggling in the slightest, I was thinking of using a pyrp-pen and try to get some localised heat onto the casing, its too difficult and risky to use a blow lamp even a small one. If i can get a few heat cycles into it there may be a chance of it breaking them lose. I don't understand why the tolerance is so tight on a sensor that is fixed by a 6mm hex bolt, just doesn't make sense? Quote Link to comment Share on other sites More sharing options...
Ordnator 2 Posted September 14, 2022 Share Posted September 14, 2022 (edited) Hi CB, I suspect it is more likely to be dissimilar metal corrosion coupled with salt rich water spray (nature's electrolytic fluid) + time. Try some anti-seize spray and a little time (not 20 years though). When I replace / refit my sensors I use a thin film of a non-emulsifying grease (Vaseline). Similar effect to using it on your battery terminals. My CAN$0.02. Best regards, Mick Edited September 14, 2022 by Ordnator 2 Quote Link to comment Share on other sites More sharing options...
Steve VH Posted September 26, 2022 Share Posted September 26, 2022 Can you drill the old one out, drastic, but you don't want to break the holding bracket or it is game over. As a side note when my 528i wouldn't start up, L jetronic, I know, but it turned out to be the ECU, maybe it is quite a delicate component, and nearly 40 years of getting hot, and cold!! located just above the glove compartment, and easy to do a swap if you have a spare. Quote Link to comment Share on other sites More sharing options...
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