No power to fuel pump fuse

[sebastianroher]

Good evening r3v,
I need a little help with my car. I recently installed a smaller walboro on my m30b35 swapped 89 325i as the old pump died. Car fired up and ran fine. I took it to the exhaust shop and they said it blew fuse 11 (fuel pump). When I got it home, I used a fused jumper to pins 30/87 which were getting power, however I am still not getting power at either side of fuse 11. Furthermore, I checked the C101 at pin 13 (fuel pump) and am not getting power at either side of the connector. The car will run with the pump hot wired to the positive terminal of the battery although it has a slight hesitation on acceleration and the throttle response isn't as crisp as I know it should be. Does anyone have any advice on what I could check? I dont want to just throw parts at this thing.

Thanks,
Sebastian

[It's Soda Not Pop]

The Walbro pulls more amps. You need to use a 10a or 15a fuse

[It's Soda Not Pop]

I use a 15a for my Walbro

[sebastianroher]

I use a 15a for my Walbro

I put a larger fuse in but power isn't making it to the fuse is what I'm saying. I don't understand what it could be.

[It's Soda Not Pop]

Do you have a 13 button OBC?

[sebastianroher]

Do you have a 13 button OBC?

Yes

[It's Soda Not Pop]

Ok there is code that was a feature for the E30 that you to secure your car from being able to be started (tampered with/hot wired/stolen). The 13 button OBC is known to have issues with age and cause no starts.

https://www.r3vlimited.com/board/forum/e30-technical-forums/engine-drivetrain/m20/361222-fuel-system-test-issues-with-jumping-relay-obc-related

[sebastianroher]

Ok there is code that was a feature for the E30 that you to secure your car from being able to be started (tampered with/hot wired/stolen). The 13 button OBC is known to have issues with age and cause no starts.

https://www.r3vlimited.com/board/for...ay-obc-related

Interesting to note from that thread you shared, mine is saying -30°C on the OBC and I'm in FL so that is definitely off. What gives the OBC the temp reading? I threw another ground wire on the engine and she fired right up so maybe that's what was causing it? Nothing like dealing with these cars and their old wiring.

[It's Soda Not Pop]

There is a temp sensor in the Brake duct tube on the Driver's side. Yours might be bad and or missing.

[It's Soda Not Pop]

Yeah a grounding issue can cause a lot of problems. I hope she runs for you now

[sebastianroher]

Yeah a grounding issue can cause a lot of problems. I hope she runs for you now

Thanks, me too!

[sebastianroher]

Welp, my issue is back... The car sat for a few days (we had a hurricane pass through) and when I went to start it again, nothing. No power to fuel pump fuse. I am really stumped!

[D3R3K]

fuse 11 is after the fuel pump relay, and is only energized when the main relay is powered. have you tried a good relay for both?

[sebastianroher]

fuse 11 is after the fuel pump relay, and is only energized when the main relay is powered. have you tried a good relay for both?

I believe I figured it out. I had a loose connection at the main power distribution block. On top of that, the previous owner had swapped the relay location of the fuel pump to the last position instead of the middle so once I figured all that out I swapped it around and got her going. Thanks for your help!

Now I'm chasing a slight idle quality issue but I think I'm moving in the right direction.