No power to the fuel pump

[Bimmerista]

Well, a few days ago, the e30 developed a hard start issue when the engine was cold. It would take approx 3-4 times of cranking before the motor fires up. Once the car was running, it would drive fine with no issues. This problem started a last week when the temperature outside dropped to 40F at night.

After I let the car sit a few days, I tried to start it and it wouldn't fire up anymore. Just yesterday, I installed a BRAND NEW VDO fuel pump and nothing. I tested out several spare relays and still nothing. I took a test light to Fuse #11, which regulates fuel delivery to the pump and it failed. So I replaced it with another good fuse and it failed still.

Now...I tested port #11 and its getting no power. There is no power going to the fuel pump. Where do I go from here??

[vertbmw]

It appears that the relay is before the fuse, so if the fuse does not have power than the relay may not be powering the fuse. The relay will only power the fuse if power is sent to the coil side of relay from the motortronic control unit. Here is a diagram that is helpful. http://www.armchair.mb.ca/~dave/BMW/e30/

[jcbrown630]

CPS? The dme won't ground the main relay that controls the fuel pump if its not getting timing data from the CPS. You can check that by manually turning the motor and listening for the relay clicking. just a few degrees will trigger the relay.

[stevefromnewo]

just been thru this whole ordeal.for a complete step by step diagnosis and how to solve your situation:
google" fast times bavarian autosports". you want to click on the third i think newsletter down-the one which is newsletter 2007_n407.download it.scroll down to the article "my car wont start".print it out.this covers all the diagnostic basics you will have to go thru. mine turned out to be a bad cps.
steve

[Sigsaucer647]

I had this same problem, and then when I traced for power there was no power to the fuel pump/relay/fuse

It turned out to be the inline fuse in the positive cable. Its in the trunk about a foot from the terminal.

[txtorquemade]

I had this same problem, and then when I traced for power there was no power to the fuel pump/relay/fuse

It turned out to be the inline fuse in the positive cable. Its in the trunk about a foot from the terminal.

I'd check that next Mike, for sure. Easy fix.

M

[T77911S]

when you say fuse 11 failed, do you mean it blew? or it just does not have power on it.

check for power at terminal 30 on the relay socket. it should be hot all the time.

you can then jumper 30 to 87 (87a?) to make the FP run.

im not sure what you are doing to make the FP rly energize to check for power on fuse 11, but if it keeps blowing, you have a short between the fuse and the pump.
are you using a MM or a testlight?

[thejlevie]

Are you checking for power to the pump when cranking the engine? The pump only runs when the DME sees timing data from a rotating engine.

Is there spark when cranking?

[jcbrown630]

Are you check for power to the pump when cranking the engine? The pump only runs when the DME sees timing data from a rotating engine.

Is there spark when cranking?

^^^THIS - same thing i said. These cars dont prime the fuel system.

[T77911S]

i only noticed mine would run AFTER i let off the start switch. if the car did not start, when i go from start to run, the pump would run for 2-3 seconds. i did not hear mine run in the start position, and believe me, my pump was REALLY loud.

[Bimmerista]

Problem solved, the culrpit: Crank Position Sensor

[txtorquemade]

Got it going then, good for you. Vrooooooom.

[e30cabriolet]

I have a '92 e30 cabrio, the car was idling and died, I have had fuel pump issues so knew to check the fuse, that I had power at #30 and to jump 30 & 87. No matter what I did no start, or power to the pump.

I got a new CPS and no start, the pump runs and so does the car with power to the pump outside the pump's wiring.

What am I missing?

I said f00k it, wired the pump to the rear window "defogger" so now I have a 30A fuse, the same relay and a switch. (don't care I lost the blower, it is a joke anyway)

[82eye]

try a known good relay. clean relay contacts at the female side as well.

[e30cabriolet]

I had already been through all that. It has a new Bosch relay, new BMW socket (it was a mess) I had already replaced the fuel pump, the CPS checked the fuse and throttle body, C191 wire harness, injectors rebuilt Bav AFM, etc etc.

Thanks