 Fuel pump issues-trying to help remote troubleshoot another members car |
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| Tdskip |
 Jun 18 2020, 07:51 AM
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#1
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Advanced Member  Group: Members Posts: 3,686 Joined: 1-December 17 From: soCal Member No.: 21,666 Region Association: None 
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Good morning. Trying to help someone else out here to pay back all the assistance you folks have given me. The car in question is a 1971 that’s running its factory fuel injection system. The car started and ran last week for about a quarter mile and then stumbled and died and had to be towed home.
-We can’t hear the fuel pump running and there’s no fuel flow to the filter. -The rest of the electrical system energizers, he’s got lights in open door bangs and bongs and everything else that you’d expect with the ignition key in the run position -he intalled new fuel pump relay, I don’t have the brand or spec on that, so I’m treating that as somewhat suspect Given this, and the fact that it did start and run properly, my inclination is that we have a problem with energizing the fuel pump. That leads me to thinking there should be two tests that we do, the first is to make sure that we have 12 V at the fuel pump relay and then make sure that we’ve got 12 V at the actual fuel pump itself. I also want to check on the following simple idea – with the ignition in the run position if we simply jumper the fuel pump relay wind it tell us right away whether or not the relay is the issue? In other words, if we jump or 12 V between the relay prongs in the fuel pump energizes that tells us that it’s a simple relay problem, correct? If we’ve got 12 V at the relay but the fuel pump is not energize then I believe the next check would be to make sure with everything energized that we’ve got 12 V at the fuel pump and a good ground, sound right? If we’ve got 12 V everywhere including on the fuel pump and good grounds then that suggests that the fuel pump itself just gave up the ghost, correct? Thanks for the help, I’d really like to be able to help this guy out so I appreciate the responses and coaching on properly diagnosing this. |
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Replies(1 - 4)
| BeatNavy |
Jun 18 2020, 07:58 AM
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#2
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Certified Professional Scapegoat Group: Members Posts: 2,924 Joined: 26-February 14 From: Easton, MD Member No.: 17,042 Region Association: MidAtlantic Region
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| dr914@autoatlanta.com |
Jun 18 2020, 08:39 AM
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#3
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914 Guru Group: Members Posts: 7,857 Joined: 3-January 07 From: atlanta georgia Member No.: 7,418 Region Association: None |
there is a troubleshooting procedure in the back appendix of the 914 "tech tips 700" book that will enable him to get the car running again. Basically the fuse the relays and the grounds
QUOTE(Tdskip @ Jun 18 2020, 06:51 AM)  Good morning. Trying to help someone else out here to pay back all the assistance you folks have given me. The car in question is a 1971 that’s running its factory fuel injection system. The car started and ran last week for about a quarter mile and then stumbled and died and had to be towed home. -We can’t hear the fuel pump running and there’s no fuel flow to the filter. -The rest of the electrical system energizers, he’s got lights in open door bangs and bongs and everything else that you’d expect with the ignition key in the run position -he intalled new fuel pump relay, I don’t have the brand or spec on that, so I’m treating that as somewhat suspect Given this, and the fact that it did start and run properly, my inclination is that we have a problem with energizing the fuel pump. That leads me to thinking there should be two tests that we do, the first is to make sure that we have 12 V at the fuel pump relay and then make sure that we’ve got 12 V at the actual fuel pump itself. I also want to check on the following simple idea – with the ignition in the run position if we simply jumper the fuel pump relay wind it tell us right away whether or not the relay is the issue? In other words, if we jump or 12 V between the relay prongs in the fuel pump energizes that tells us that it’s a simple relay problem, correct? If we’ve got 12 V at the relay but the fuel pump is not energize then I believe the next check would be to make sure with everything energized that we’ve got 12 V at the fuel pump and a good ground, sound right? If we’ve got 12 V everywhere including on the fuel pump and good grounds then that suggests that the fuel pump itself just gave up the ghost, correct? Thanks for the help, I’d really like to be able to help this guy out so I appreciate the responses and coaching on properly diagnosing this. |
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| Olympic 914 |
Jun 18 2020, 09:04 AM
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#4
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Group: Members Posts: 1,668 Joined: 7-July 11 From: Pittsburgh PA Member No.: 13,287 Region Association: North East States
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the AAR is activated at the same time as the fuel pump. so an easy check might be to test for power at the plug for the AAR.
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| Tdskip |
Jun 18 2020, 10:24 AM
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#5
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Advanced Member Group: Members Posts: 3,686 Joined: 1-December 17 From: soCal Member No.: 21,666 Region Association: None
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Thanks gentlemen.
Good tip on AAR. |
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