No fuel pump action in new m50 swap

[bimmerboy02]

It's the first day I tried starting my swap. NVm50 from a 92 325i manual into an 87is manual, I'm 99% it's all right in the c101/x20 (I went through the ETMs and found it all, then when I was looking through no start threads earlier this day I found a thread in which Ely(rs4pro) made an adapter for the exact swap I'm doing and ours were the same) Car turns over, cranks real strong but I'm not getting a fuel pump. I have had both fuel lines off the rail and had no fuel coming out. I tried starting fluid and could get it to run so I am fairly sure I have spark, which means my CPS is working and my ecu should be signaling for the fuel pump, correct? I have tried jumping the FP relay to no avail. Can't get any voltage across the fuse either.

I know my spark test isn't definitive but I didn't have a helper. Usually running on starting fluid means spark(highly doubt it was just dieseling)

Like I said, I had no helper so it was hard to test voltage on the FP fuse but I tried and think I was successful, so until I see voltage going to the pump I'm going to say the pump is good.

Any ideas?

[bimmerboy02]

I can't get power at the ecu.

I don't know how it runs on starting fluid then...

But does that make sense, given that it cranks and everything else has power? ECU grounds checked out fine

[BMW_TUNER]

Try turning the key on and grounding the Brown/ whatever wire on the Fuel pump relay. See if you can hear the pump running. How are you putting power into your harness? How many and where are you grounds?

[bimmerboy02]

I've tried jumping the fuel pump relay but couldn't get anything. Would grounding 85 on the relay be any different?

Power is e36 starter cable, hooked up to the B+ post in the engine bay, by a battery terminal on the post. I also have the ring terminal from the harness bolted to that battery terminal. Grounds are the two stock e36 ones by the diagnostic connector which i bolted to the stock ground location on the strut tower. And then the strap from the drivers engine mount arm to the frame rail

[BMW_TUNER]

Grounds sound good. THe relay can be grounded with the key on and this will tell yo whats up witht he pump. I had no luck jumping mine. I just grounded the brown one and the pump ran until I stopped grounding.

[bimmerboy02]

Ok I'll try that, maybe the fuel pump wiring is a bit more complicated than most cars I'm used to.

The no power at pin 26 still screams at me though... I don't see why I don't have it there. It should be a constant battery feed. I'm getting power to everywhere in my engine harness except my ecu...

[BMW_TUNER]

You did not power the Black and Purple wire #7 on the E36 Harness did you

[lennon]

check the second wire running from your battery in the trunk forward. there's a fusible link in the wire under the carpet that goes bad. check it out. mine was fucked a while ago and kept my ecu from getting full power. same situation as you but with no swap.

[bimmerboy02]

Ah I got ! just started an m50 open header at 2 in the morning outside...ooops :D But I got it.
It was the power wire that is in the branch near the diagnostic connector...when I said I had two i meant two seperate ones. I did not figure BMW would put a power and a ground in the same bundle and keep the colors hidden. BMW TUner got me thinking through all my grounds/powers again and came across people saying "check the colors, it's trickier than you think" and so I got it. Just needed some people to ask questions and do archive searching around here.. All it takes usually/
Ah! A new m50 swap has been successful! Thanks

[MIKe30]

nice, congrats!

[BMW_TUNER]

Congrats good work

[bimmerboy02]

Yea it was pretty rookie, felt pretty stupid, but the sound of a non muffled m50 made me not really care. I should have confirmed all powers and grounds properly rather than just assume "oh these two are together, and I know ones a ground both must be" . Stupid but I'm so happy that the swaps complete and successful

Thanks guys

[SamE30e]

Ah I got ! just started an m50 open header at 2 in the morning outside...ooops :D But I got it.
It was the power wire that is in the branch near the diagnostic connector...when I said I had two i meant two seperate ones. I did not figure BMW would put a power and a ground in the same bundle and keep the colors hidden. BMW TUner got me thinking through all my grounds/powers again and came across people saying "check the colors, it's trickier than you think" and so I got it. Just needed some people to ask questions and do archive searching around here.. All it takes usually/
Ah! A new m50 swap has been successful! Thanks

Same thing I did.