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Discussion Starter · #1 ·
I have a 98 540i6. prod date 3/98 I replaced the motor since the original had two broken rods. Basically my problem is that this car cranks for a while. I would spray starting fluid in the throttlebody you could heard and feel the motor jolt like it wants to start so Im guessing I get spark The fuel pump doesnt turn on when the key is in the on position. however the pump works when I bridge it from the battery itself I take out one injector fuel pours out of the rails but doesnt go through the injectors. I replaced literally every fuse. I had extra relays and replaced the ones in the dme box and trunk. light green, brown/tan, pink(abs), tan(with fuses in it). question is what else could I try/replace to get it work, and if this doesnt work what should I do take it to a euro shop? also had replace the camposition sensor. ordering a crank position sensor and new relays.
 

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Have you checked the fuses in the back side of the DME box?
A bad crank sensor will prevent the fuel pump from running.
 

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Discussion Starter · #3 ·
Well when I put my multi-meter to the relays some make the needle move and green ones don't move at all. So I don't know how to actually test them. By any chance do you have a picture of the dme/trunk relay/fuse locations labeled so I know which one I can pull and properly test. and does the crank position sensor also stop the fuel injectors to just shoot out fuel. if not what else could I check besides the relays.
 

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Read Jim's post again. A bad crank sensor inhibits the fuel pump.
 

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Discussion Starter · #5 ·
Yeah and then read my message again. Instead of wasting my time by saying read jims message again. I asked how to test relays and what else to do to figure my problem??? Yup
 

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Your post indicated that Jim's reply had not sunk in, since you were still apparently confused about the function of the crank sensor.
 

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Your post indicated that Jim's reply had not sunk in, since you were still apparently confused about the function of the crank sensor.
Guess some just like to start looking at the wrong end.

If the fuel pump relay isn't working it is either not getting power (could be a crank sensor problem) or maybe the relay is bad.
I haven't seen that you have checked the fuses (Fuse Panel 3) in the back of the DME box yet, there are 5 fuses there, F2 is for the fuel injectors.

Testing a relay is easy, apply 12 volts to the coil pins. Put one meter lead on the common pin. The other lead goes on the NC and then the NO pin. You are looking for the contacts to make and break when the relay switches. The ohms scale is used.
 

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Discussion Starter · #8 ·
and how do you test the relays themselves is the question? tried putting them to a multi-meter on 30 and 87 I think and the needle doesnt move for some even the new ones I bought.
 

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If you replaced the engine, make sure all your grounds are all connected. The car will not start if the grounds are not properly connected. I had several mechanics warn me about this problem when I replaced an engine in a 328. On that car, the ground was passenger side at the motor mount.
 

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Discussion Starter · #10 ·
Even before I replaced the motor the original motor didnt start either even though the fuel pump didnt turn on either. So I may have to eliminate the ground. Where would the grounds be on a e39 540i
 

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and how do you test the relays themselves is the question? tried putting them to a multi-meter on 30 and 87 I think and the needle doesnt move for some even the new ones I bought.
Relays have 2 inputs constant power in and a switched power, and have one out put which puts the constant input on the output terminal when switch goes high.

You can detach relay...connect voltmeter on output...constant 12v on input and then have a free wire to touch to switched input. You should see out put go high and low as you apply 12v
 

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Even before I replaced the motor the original motor didnt start either even though the fuel pump didnt turn on either. So I may have to eliminate the ground. Where would the grounds be on a e39 540i
There should be a large ground at the front passenger side motor mount. One in the spark area on middle coils...and random brown clusters on each side of engine and in the trunk by the relays.
 

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Discussion Starter · #13 ·
Oh I see so basically in a simple term. I would have to do is connect the relays with a constant 12v power source to whatever prong needed to "flip the switch" inside and connect and test with just my
Multi-meter on the prongs to test
 

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You have to pull the key out of the ignition each time to force the fuel pump on.

I've seen my fair share of broken crank sensors with tranny and engine replacements. If it wasn't removed during the swap it's probably broke.
 

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Discussion Starter · #17 ·
Even in the old motor that was in it before the replacement. It still didnt start. It just cranks like it is now. Depending on the battery a fast or
Slow cranking
 

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Discussion Starter · #20 ·
Alright guy figured out the problem with my 540i with th m62b44. The problem was the DME needing to be reprogram is it now running as of last week. so to the guys with this similar problem where you don't get fuel when you turn the key to the on position, you get spark, no blown relays/fuses, did the fuel pump bridge in the rear trunk/boot, have a good camshaft and crankshaft sensors. You would most likely have to get a dme/ews reprogram or exchange.
 
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