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> Fuel Pump runs constantly., Relocated and rewired by PO.
Crash207
post Jun 8 2011, 05:10 PM
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Hey guys.

73 1.7 D-Jet. 3 port Bosch fuel pump (now located under the fuel tank) runs constantly and is a bit loud. I read that it is supposed to run for 1-1.5 seconds and stop with key on engine off. Checked wiring and found it is wired directly to Fuse #8 on the fuse panel. Where should it be wired?

Side note. Car sat for 5 years before i rescued it and the fuel pump had power but didn't run until i whacked it a few times.

Thanks in advance, You guys are awesome and your expertise is much appreciated.
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jsayre914
post Jun 8 2011, 05:14 PM
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QUOTE(Crash207 @ Jun 8 2011, 07:10 PM) *

Hey guys.

73 1.7 D-Jet. 3 port Bosch fuel pump (now located under the fuel tank) runs constantly and is a bit loud. I read that it is supposed to run for 1-1.5 seconds and stop with key on engine off. Checked wiring and found it is wired directly to Fuse #8 on the fuse panel. Where should it be wired?

Side note. Car sat for 5 years before i rescued it and the fuel pump had power but didn't run until i whacked it a few times.

Thanks in advance, You guys are awesome and your expertise is much appreciated.

If you look under the car right behind the passenger seat, there is usually a white plug hainging there, or mabey ziptied up in the bay. If the PO rewired it direct to the fuse box, I would suspect there is an aftermarket switch in the cabin eithere on the dash or center console to kill it (IMG:style_emoticons/default/confused24.gif)
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Crash207
post Jun 8 2011, 05:20 PM
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No aftermarket switch but i could add one. Should it be wired to the plug behind the pass seat in your opinion?
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SirAndy
post Jun 8 2011, 05:26 PM
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QUOTE(Crash207 @ Jun 8 2011, 04:20 PM) *
No aftermarket switch but i could add one. Should it be wired to the plug behind the pass seat in your opinion?

I don't have his opinion, but i'll give you mine. (IMG:style_emoticons/default/biggrin.gif)

IMHO, your current setup is dangerous!

You should use the stock wiring and plug to run your fuel-pump. That way, it will be controlled by the FI brain.

Simply run two wires from your current pump location through the center tunnel to the lower engine bay, add two male spade connectors to the wire ends and plug them into the stock plug.
(IMG:style_emoticons/default/shades.gif)
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jsayre914
post Jun 8 2011, 05:29 PM
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Someone eleses opinion (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/chowtime.gif)

http://www.pelicanparts.com/techarticles/9...mp_relocate.htm

(IMG:style_emoticons/default/shades.gif)
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SirAndy
post Jun 8 2011, 05:32 PM
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QUOTE(jsayre914 @ Jun 8 2011, 04:29 PM) *
Someone eleses opinion (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/chowtime.gif)

http://www.pelicanparts.com/techarticles/9...mp_relocate.htm

Why the hell would someone recommend cutting a perfectly good stock harness if it's totally unnecessary?

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Tom
post Jun 8 2011, 07:09 PM
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There is a good reason why the fuel pump only runs on one of three times.
1- for 1.5 seconds when the key is turned to on to prime the fuel system,
2- when the key is turned to start,
3- when the engine is turning more than 100 RPM's.
If you have a fire in the engine bay and the fuel pumps continues to run, the fuel feeds the fire, not a good thing! With key on and engine stopped, the pump should stop as it's really not needed to support running. These car are noted for having fires!
It is in your best interest to get it fixed correctly.
Tom
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jsayre914
post Jun 8 2011, 08:22 PM
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QUOTE(SirAndy @ Jun 8 2011, 07:32 PM) *

QUOTE(jsayre914 @ Jun 8 2011, 04:29 PM) *
Someone eleses opinion (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/chowtime.gif)

http://www.pelicanparts.com/techarticles/9...mp_relocate.htm

Why the hell would someone recommend cutting a perfectly good stock harness if it's totally unnecessary?

(IMG:style_emoticons/default/confused24.gif)

(IMG:style_emoticons/default/agree.gif)
Why in the hell does everyone move it to the front anyway. I have owned 2 914s with the fuel pump in the stock location with no problems. Today was 100degreees and I drove the hell out of it, stopped for gas, still no problem.
(IMG:style_emoticons/default/confused24.gif) (IMG:style_emoticons/default/beerchug.gif) (IMG:style_emoticons/default/beer3.gif)
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r_towle
post Jun 8 2011, 11:25 PM
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Its really not a safety issue.
the pump turns on for 1.5 seconds to prime the system and get it up to pressure.
All electrical power is diverted to the starter when cranking...all of it.
As you know...our starters need all they can get.

After the car has started, the fuel pump is running constantly till you turn off the car.

If its loud, mount it on rubber isolators.

Rich
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Derek Seymour
post Jun 8 2011, 11:37 PM
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Mine is from a fucking Volvo and sounds like a sewing machine, but it works right because of the previously mentioned proper wiring.
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McMark
post Jun 8 2011, 11:53 PM
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QUOTE(r_towle @ Jun 8 2011, 10:25 PM) *

Its really not a safety issue.
the pump turns on for 1.5 seconds to prime the system and get it up to pressure.
All electrical power is diverted to the starter when cranking...all of it.
As you know...our starters need all they can get.

After the car has started, the fuel pump is running constantly till you turn off the car.

If its loud, mount it on rubber isolators.

Rich

I totally agree, up until the point that something unexpected happens. IMHO, build a safe car. Especially when all we're talking about is running some wires. (IMG:style_emoticons/default/rolleyes.gif)
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Crash207
post Jun 9 2011, 09:27 AM
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So if for some reason the old wiring is not there, where should i connect the wires, to wire it properly.
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Cap'n Krusty
post Jun 9 2011, 09:48 AM
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If the pump is loud, it's been relocated, and you had to bang on it to get it to run, it already had 3 strikes against it. Loud: pinched inlet line, no rubber isolators, or bad bearings; stuck at some point, so you had to unstick it (it'll stick again, guaranteed); and relocated by someone who didn't know what he/she was doing. You're pressurizing lines that weren't meant to be pressurized, and there's a REAL good chance there are mismatched fittings and hoses hidden under the tank. The increased possibility of fire comes to mind.

Better get after it!

The Cap'n
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Crash207
post Jun 9 2011, 10:04 AM
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I replaced all the fuel lines with pressure rated fuel hose but i need rubber isolators. Where would the original +12 volt power to fuel pump start or should i run new wires to the relay board?
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Tom
post Jun 9 2011, 10:13 AM
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Rich said, "All electrical power is diverted to the starter when cranking...all of it."
Rich,
This is not true, and you say it is not a safety issue, well I would disagree. It would certainly be a safety issue if the pump ran all of the time and you had a fuel leak. Just turning the key to on could cause a lot of fuel on the ground rather quickly, don't you think.
Look at the relay board schematic. Follow the yellow wire trace from pin 6 of the 12 pin connector. It also goes to the ECU to allow ground to appear at pin 86 of the fuel pump relay. So, among other things, such as the coil, the fuel pump is powered up at start, not just the starter.
Tom
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Cap'n Krusty
post Jun 9 2011, 10:25 AM
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QUOTE(Crash207 @ Jun 9 2011, 09:04 AM) *

I replaced all the fuel lines with pressure rated fuel hose but i need rubber isolators. Where would the original +12 volt power to fuel pump start or should i run new wires to the relay board?


I was referring to the plastic lies through the tunnel, which were NOT designed to be under pressure. Actually, the '75-'76 cars used different plastic lines, which are rated for pressure.

The Cap'n
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rjames
post Jun 9 2011, 11:48 AM
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The PO rewired my fuel pump this way, too. (IMG:style_emoticons/default/headbang.gif) Hope I can get it wired it correctly without pulling the gas tank.
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r_towle
post Jun 9 2011, 12:43 PM
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QUOTE(Cap'n Krusty @ Jun 9 2011, 11:48 AM) *

If the pump is loud, it's been relocated, and you had to bang on it to get it to run, it already had 3 strikes against it. Loud: pinched inlet line, no rubber isolators, or bad bearings; stuck at some point, so you had to unstick it (it'll stick again, guaranteed); and relocated by someone who didn't know what he/she was doing. You're pressurizing lines that weren't meant to be pressurized, and there's a REAL good chance there are mismatched fittings and hoses hidden under the tank. The increased possibility of fire comes to mind.

Better get after it!

The Cap'n

I am inclined to agree here.
This is a side of the road tow truck issue, with or without a fire involved.

Get it fixed.

Rich
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