 fuel pump power failure |
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| Cvrguy |
 Jul 13 2026, 11:57 AM
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#1
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Newbie  Group: Members Posts: 37 Joined: 18-September 25 From: Los Angeles Member No.: 28,995 Region Association: None  |
I have a '73 914 2.0 with a well sorted D-jet system. Driving the other day, I came to a stop and the engine died. When I tried to restart it, I didn't hear the fuel pump cycle when the key was turned. Sure enough, when I checked with the multimeter, no voltage to the pump when the key was turned. I had previously relocated the fuel pump to the front, extending the power lead from the rear to the front through the center tunnel.
Troubleshooting so far: 12v directly to the pump shows it running fine, correct continuity from the rear to the front on the power lead, replaced the relay. As far as I can determine, the problem lies between the circuit board and the original 12v lead. I had previously replace the circuit board and both multi-pin connectors. The ground point for both the circuit board and the fuel pump are perfect. I replaced the ignition switch a few months ago as well Is there another common failure point that I can investigate? |
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| JamesM |
Jul 13 2026, 12:03 PM
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#2
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Advanced Member Group: Members Posts: 2,273 Joined: 6-April 06 From: Kearns, UT Member No.: 5,834 Region Association: Intermountain Region |
QUOTE(Cvrguy @ Jul 13 2026, 09:57 AM)  Is there another common failure point that I can investigate? There are a TON of failure points in that circuit, most are in or around the relay board. Jeff Bowlsby has a document that goes over troubleshooting all of them, ill see if I can dig it up. I find its usually due to one of the crimped traces in the relay board connection losing conductivity though. Edit: Link below https://bowlsby.net/914/Classic/zTN_FI_FPChecklist2.pdf Another point to note is that often the trace falures in the relay board will often only fail under certian heat or pressure conditions so the board with bench test out fine but fail when connectors are installed or after 10 minutes of driving and things get hot. |
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| friethmiller |
Jul 13 2026, 12:06 PM
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#3
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Senior Member Group: Members Posts: 1,384 Joined: 10-February 19 From: Austin, TX Member No.: 22,863 Region Association: Southwest Region 
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I had this problem once. It was the connection at the battery. I found this out after pushing the car up the remainder of the hill it stranded me on. (IMG:style_emoticons/default/chair.gif)
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| porschetub |
Jul 13 2026, 01:55 PM
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#4
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914 Guru Group: Members Posts: 5,137 Joined: 25-July 15 From: New Zealand Member No.: 18,995 Region Association: None |
QUOTE(friethmiller @ Jul 14 2026, 06:06 AM) I had this problem once. It was the connection at the battery. I found this out after pushing the car up the remainder of the hill it stranded me on. (IMG:style_emoticons/default/chair.gif) My fault was the power control relay ,changed that and all good ,cheers. |
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| Cvrguy |
Jul 13 2026, 02:04 PM
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#5
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Newbie Group: Members Posts: 37 Joined: 18-September 25 From: Los Angeles Member No.: 28,995 Region Association: None |
Thanks so much for the checklist from Jeff. Just what I was looking for!
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