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ado ado is offline
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914 2.0 f.i. no whirr at fuel pump

Had some issues last summer starting the car after a long run then nadda.
the fuel pump is new, ran fine but now has no power. Replaced relays and fuses on the board and still no power. the pump powers up with a jump so i know it works.
Checked some wiring and found nothing yet.
any input would be helpful.

Old 04-09-2019, 04:11 PM
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First: Are you sure the pump should be running? It runs for about 1.5 seconds when the key goes from "off" to "on", then stops until the starter is cranking. It does not run the whole time the ignition is on.

Quick and easy relay check can be done by swapping the relay into one of the headlight lift sockets. If the headlight still goes up and down, the relay is working. Swapping a part is generally no substitute for testing it, unless the new part is known good.

The pump is run by the FI. If the FI doesn't get power and ground, it won't be able to trigger the fuel pump relay. The "power supply" relay on the relay board sends power to the FI when the key is on. Check that it is OK. Check all grounds, particularly the one under the relay board and the one on the rear crankcase seam.

If you ground the left-front pin of the four-pin connector at the left-rear of the relay board, does the pump run when the key is on? If so, the pump relay is good, and the problem is that the FI isn't telling the pump to run.

This isn't a complete troubleshooting list, but it should at least get you started.

--DD
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Old 04-10-2019, 07:16 AM
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ado ado is offline
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you are right on the pump running for 1.5 seconds when the key is goes to on, but it doesen't run at all ( it used to).
i tried swapping relays from working headlights and that didn't work, also swapped fuses on relay board with new ones.
i will look into the ground under the board and crankcase seam.

thanks David
Old 04-10-2019, 01:41 PM
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Your relay board may be at fault.
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Old 04-11-2019, 12:07 PM
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update....
swapped relay boards nadda.
checked crank case ground and all is new and good.
quick check on grounds under relay board, (one seems somewhat loose but still connected). i will go back and pull it all out for complete check.
i'm going to have the boards tested.
any other info would help.
thanks
Old 04-14-2019, 10:16 AM
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I chased the same problem for a while. And mine even cropped up while driving.

Ultimately, the problem was a possible failed relay board and bad relays.

Reason I say "possible" is that when I did get a good relay board and relays, I also noticed that the split male pins coming from the engine wiring harness to the board (on the firewall end of the relay board) were compressed together and possibly not making good contact. So I took the time to use a razor blade to CAREFULLY spread open the male split pins so they had more tension on the female sockets, and coated everything in dielectric grease. Problem resolved.

Never went back and re-tested the old board. Was it the pins or was it the board? Dunno.

My quick test for relays (do the same razor-spread-pins and dielectric trick) is to identify the blower motor circuit and insert all relays in there with the key on and heater lever full up. I can test each and every relay. Good ones get a silver Sharpie check, bad ones get basketball-shot testing into the garbage can.

Another top tip: assuming you don't have rear window defogger, use that slot to hold a spare relay*. And mark on the board what each relay does so that if your fuel pump relay craps on the Interstate it's a quick swap. I also keep a jumper wire taped to the inside of the board cover, as well as marking the pump relay circuit on the board itself for a quick insertion. And use a Sharpie to mark lines on how they align to the board so you don't have to think about it as 18-wheelers come whizzing by 10 feet away.

*And even if you do have a window defogger, it's still a good place for a critical spare relay.

Last edited by GregAmy; 04-17-2019 at 05:44 AM..
Old 04-16-2019, 06:55 AM
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ado ado is offline
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Thanks for the tip I will check that out and does anyone know what would be a good Sealer under the relay board where it's cracked?
Old 04-16-2019, 01:58 PM
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Quote:
Originally Posted by GregAmy View Post
I chased the same problem for a while. And mine even cropped up while driving.

Ultimately, the problem was a possible failed relay board and bad relays.

Reason I say "possible" is that when I did get a good relay board and relays, I also noticed that the split male pins coming from the engine wiring harness to the board (on the firewall end of the relay board) were compressed together and possibly not making good contact. So I took the time to use a razor blade to CAREFULLY spread open the male split pins so they had more tension on the female sockets, and coated everything in dielectric grease. Problem resolved.

Never went back and re-tested the old board. Was it the pins or was it the board? Dunno.

My quick test for relays (do the same razor-spread-pins and dielectric trick) is to identify the blower motor circuit and insert all relays in there with the key on and heater lever full up. I can test each and every relay. Good ones get a silver Sharpie check, bad ones get basketball-shot testing into the garbage can.

Another top tip: assuming you don't have rear window defogger, use that slot to hold a spare relay*. And mark on the board what each relay does so that if your fuel pump relay craps on the Interstate it's a quick swap. I also keep a jumper wire taped to the inside of the board cover, as well as marking the pump relay circuit on the board itself for a quick insertion. And use a Sharpie to mark lines on how they align to the board so you don't have to think about it as 18-wheelers come whizzing by 10 feet away.

*And even if you do have a window defogger, it's still a good place for a critical spare relay.
Great info and tips here !! ^^^
Thank you!
Old 04-17-2019, 10:04 AM
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Hey there, and welkom to the not working fuelpump club!
Mine gave up working last season, without any warning, and all of the above tests were OK.
I connected the pump directly to a powersource on contact, so the pump works permanently now when i put on ignition. The engine will start for a second or 2, and then he goes to sleep. Can the pump work without the relay board, or is there a lack of fuel pressure due to the manner of powering the pump?
Thanks for any reply.

Marc
Zele
Belgium
Old 05-02-2019, 09:00 AM
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The pump stays constantly on when the engine is running; the relay is energized by the coil. It was done that way as a safety feature, so that if you crash and the engine stops, so will the fuel pump.

So it's not hurting anything (except safety) to wire it that way.

I had a problem a couple years ago with similar symptoms: starts, runs a couple seconds, then stops. Turned out to be a bad diaphragm on the MPS. I had Chris Foley rebuild the MPS and the car runs like a charm.
Old 05-03-2019, 05:31 AM
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ado ado is offline
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i checked all grounds, relays and had the board tested. nada
i just read the reply on hooking up the pump direct.
i am willing to try this to get the car running again and hoping for the best.
thanls
Old 05-19-2019, 09:00 AM
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The pump is powered by one of the two fuses on the relay board. Make sure those fuses are in good condition and making solid contact. Clean the contacts with emery cloth or a wire brush or some such.

The fuel pump circuit also powers the Auxiliary Air Regulator, the air valve that lets air go around the throttle valve when the engine is cold. If the single wire that goes to the AAR shorts to ground, the fuel pump fuse will pop and the pump will not run.

--DD
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Old 05-19-2019, 09:38 AM
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ado ado is offline
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after checking all of the above and not find the fault i hooked up the pump directly.
i got the car running, but i admit i was nervous on doing that.
thanks again
Old 05-22-2019, 04:00 PM
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Hi there,

I solved my problem with the fuel pump! I cleaned the relay-board with electro spray, and opened all the contact pins with a cutting knife at the top. After that the pump worked as she should, so end of misery.

Marc
Zele, Belgium
Old 05-28-2019, 05:37 AM
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Old 05-28-2019, 07:49 AM
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