Fuel pump will not prime

RuskiRacer

Sergeant
Jul 17, 2019
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2009 e93 335i
Ok so if I am not getting power to the ekp where else do I look ? Replace the whole wiring harness ? On my old car thats now my parts car I remember I unplugged and re plugged that main fuel harness probably 10 times with zero issues and on mt new car I touch it once and I have a catastrophe. What else could I replace even fuse box? There is 12 volts to fuel pump fuse and the relay in the dme box
 

RuskiRacer

Sergeant
Jul 17, 2019
428
157
0
Ride
2009 e93 335i
Yeah there's only the 50 fuse in the dme box has power through it looks good as well. Relay has power going to it and should be good I put one in from my parts car that worked before I pulled the car apart. Literally just undid all the top hat parts carefully without breaking anything took out the old fuel pump, installed my 450s connected everything back together , connected the battery back and went to start the car it ran for like 5 seconds and I went on my jb4 logging and seen low pressure psi is like 5 and as im trying to start the car its not building. So now im to the point where im at where I for some reason don't have power flowing to the ekp. Any ideas from anyone would help. My new car is an 07 model year so the fuse box is the old style and im like 99% sure I know what fuse is fore the fuel pump
 

NoGuru

Lieutenant
Jan 9, 2018
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Just North of Detroit
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BMW 335is
If you have power at the fuse panel and not at the EKP, it has to be the wire right? I would find where the power ends like the EKP and start following it back to the fuse panel.
 
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RuskiRacer

Sergeant
Jul 17, 2019
428
157
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2009 e93 335i
Thats what my thought is now im not sure how it can be anything other than the wire such a wierd freak occurrence. And since that happening my battery has been dying out of nowhere, would have to put jumper cables on the car to do any testing
 

NoGuru

Lieutenant
Jan 9, 2018
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Just North of Detroit
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BMW 335is
Find out if the battery is bad or not. Bad battery's do some really strange things to the electrical systems on BMW's.
That could be your issue.
 

RuskiRacer

Sergeant
Jul 17, 2019
428
157
0
Ride
2009 e93 335i
Yeah ill probably get my buddy at autozone to swap it out for me. But this battery was running strong for me even in the cold -30 weather in mn only until I did the fuel pump is when I started noticing a parasitic drain.
 

NoGuru

Lieutenant
Jan 9, 2018
955
402
0
Just North of Detroit
Ride
BMW 335is
Yeah ill probably get my buddy at autozone to swap it out for me. But this battery was running strong for me even in the cold -30 weather in mn only until I did the fuel pump is when I started noticing a parasitic drain.
Okay, that's important information. Did you just connect the Hobbs wiring to the battery with the new setup? Maybe the replay on the wire harness is bad?
 

RuskiRacer

Sergeant
Jul 17, 2019
428
157
0
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2009 e93 335i
Yeah I do currently have it on the battery wired up that is a possibility I tried running power through the secondary harness to try to get the second pump to prime and couldn't until i I put mini jumper cables directly to the bolts on the top hat for the secondary harness
 
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martymil

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Sep 6, 2017
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if you battery is flat it will play funny buggers with the junction box, I've seen modules get damaged because of this.

Make sure you have a good battery and a decent charger like 25amp or more.

I really hope you didn't damage anything because its going to make it all that harder for you to solve the problem.

The bmw electrical system is a bitch.
 

RuskiRacer

Sergeant
Jul 17, 2019
428
157
0
Ride
2009 e93 335i
Yeah my car is dead and I'm hearing a wierd clicking from the fuse box. I'm gonna grab a new battery and a nice charger. I traced the ekp power wire down in the fuse box but not sure if id be able to swap because I have different fuse box in each car
 

martymil

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Do not swap the fuse boxes they are very different from model to model and have to be coded and firmware is very different.

I'm no expert on this but I seen it done and seen one catch fire.

I could be wrong and maybe someone else can chime in here, its just a warning and you really should inform yourself from somebody knowledgeable
before you attempt anything like this or yet get someone that does.
 

RuskiRacer

Sergeant
Jul 17, 2019
428
157
0
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2009 e93 335i
Yeah trust me I would love to avoid swapping fuse boxes. Im just tryna think of what else it could be or how else I can test the ekp power wire because if I'm getting power at the fuse somewhere along the line there has to be some sort of issue. I disconnected the secondary fuel harness to avoid any possible parasitic drains from it.
 

martymil

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If you where in Sydney I have a guy that could easily fix this with his eyes closed, you need to find an auto electrician that knows his BMW's not just
the run of the mill ones.

It wont be the wiring unless you modified something, its one of the modules that's gone bad by the sounds of it, I'm no expert but I have seen it in the past.
 

RuskiRacer

Sergeant
Jul 17, 2019
428
157
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2009 e93 335i
Yeah hahah I wish I lived near a good bmw electrician. It being one of the modules makes sense. The only code I am getting is cda6 which is ekp related. My buddy at the autozone doesn't work today so maybe I can grab the battery tomorrow. The only coding software I have is protool and it doesn't seem powerful enough for me
 

martymil

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Sep 6, 2017
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Protool is great for basic to intermediate stuff but that's about it, don't get me wrong it's a great tool and I use it a lot but nothing the the bmw tools my mate uses.

Its good to use to bring up faults on the side of the road like I did the other day stuck in the middle of nowhere with our single turbo car to find out the harness was damaged on the boost sensor when the rod let go. Quickly taped it up and kept going.
 
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RuskiRacer

Sergeant
Jul 17, 2019
428
157
0
Ride
2009 e93 335i
Yeah I agree its nice to like code injectors and reset things, simple stuff. I need like inpa or ista to show me where there voltage drop-off in the wiring harness is
 
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