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Fuel pump rewire: this look good?

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Old 06-18-14, 09:12 AM
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Originally Posted by redheddude222
I'll keep that in mind. What does it take to get to the ignition switch? My S4 has a mostly mint condition dash, and I'm afraid of things disintegrating if I try to remove anything.
Just unscrew the clamshell column surround trim and the back of the ignition switch is right there.
Old 06-18-14, 09:15 AM
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Originally Posted by clokker
Just unscrew the clamshell column surround trim and the back of the ignition switch is right there.
See my post above clocker. If he tags it there, it makes life difficult if he ever needs to replace the ignition switch.
Old 06-18-14, 12:30 PM
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The two "harnesses" involved are the fuel pump and the resistor in the engine bay. For the fuel pump pull the hatch Harper up and your will see the wiring. Just follor it 12inches up and you will find the 4 pin plug. The one in the engine bay is behind the RF headlight where the stock airbox usually sits
Old 06-19-14, 08:21 AM
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My TII has low impedance injectors. Is it still ok to cut all of the wires at the resistor, or will that affect injector operation?
Old 06-19-14, 08:39 AM
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Originally Posted by redheddude222
My TII has low impedance injectors. Is it still ok to cut all of the wires at the resistor, or will that affect injector operation?
The fuel pump resistor and fuel injectors have zero relation to each other electrically.

Just don't snip the wires so close to the plug you can't wire it up stock again if you need to.
Old 06-19-14, 09:09 AM
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I made jumpers to fit inside the plug, so I can just plug it back in later if I decide to go back to stock. I'm working on wiring in the relay now.
Old 06-19-14, 09:33 AM
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Ok, one last question (I hope). If I am reusing the stock relay, which wires (colors if possible) do I connect? I can't find a good breakdown of the wires in my Haynes manual.

It has 6 wires, 2 connectors.

4-pin connector: fat blue, small blue, fat black/yellow, small black.

2-pin connector: small black/yellow, small white/black.
Old 06-19-14, 10:15 AM
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^ The relay I listed is the EGI main relay on the driver side, between the strut tower and firewall. I couldn't find anything on a fuel pump relay.
Old 06-19-14, 10:35 AM
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Originally Posted by redheddude222
^ The relay I listed is the EGI main relay on the driver side, between the strut tower and firewall. I couldn't find anything on a fuel pump relay.
What do you want to do to the main relay?
Old 06-19-14, 11:04 AM
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The 4-pin relay in the diagram. Pins 30, 85-87. Is that a factory relay located somewhere in the car, or do I need to supply my own relay? I was assuming it was a factory relay based on the specific numbers listed.
Old 06-19-14, 11:09 AM
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Originally Posted by redheddude222
The 4-pin relay in the diagram. Pins 30, 85-87. Is that a factory relay located somewhere in the car, or do I need to supply my own relay? I was assuming it was a factory relay based on the specific numbers listed.
If you're talking about the relay used in rewiring the fuel pump then that is a different relay than the main relay, thus you supply your own.
Old 06-19-14, 11:12 AM
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Ok, thank you. Is there a common aftermarket relay that everyone uses when doing this, or do I just pick up a 4-pin relay from auto zone?
Old 06-19-14, 11:20 AM
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Originally Posted by redheddude222
Ok, thank you. Is there a common aftermarket relay that everyone uses when doing this, or do I just pick up a 4-pin relay from auto zone?
You would use a standard automotive relay found at an auto store.
Old 06-19-14, 11:22 AM
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Perfect. Thank you again.
Old 06-21-14, 02:36 AM
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I got everything wired up today. It starts and idles like normal, but throttle response has improved, there's no more hesitation when I blip the throttle, and it doesn't act like it wants to die when taking off anymore. I didn't notice the 3800 rpm stumble anymore, either.

One thing I did notice, though, is that the relay I added got very hot to the touch. Not hot enough to burn my hand, but not far off. Is this normal?
Old 06-21-14, 07:51 AM
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Originally Posted by redheddude222
I got everything wired up today. It starts and idles like normal, but throttle response has improved, there's no more hesitation when I blip the throttle, and it doesn't act like it wants to die when taking off anymore. I didn't notice the 3800 rpm stumble anymore, either.

One thing I did notice, though, is that the relay I added got very hot to the touch. Not hot enough to burn my hand, but not far off. Is this normal?
What is the amperage rating of the relay. Usually, they will say something like "30/40" with 30 meaning 30 amps constant and 40 meaning 40 amp momentary.
Old 06-21-14, 10:06 AM
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It just says 30 amp. It's tied into a 10 gauge wire with a 30 amp fuse for my aftermarket stereo. Does it sound like anything I need to worry about?
Old 06-21-14, 05:52 PM
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Originally Posted by redheddude222
It just says 30 amp. It's tied into a 10 gauge wire with a 30 amp fuse for my aftermarket stereo. Does it sound like anything I need to worry about?
Is it also powering your aftermarket stereo? How do you have this thing wired up, the best that you can explain?
Old 06-22-14, 12:26 AM
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There is a 10 gauge wire with a 30 amp fuse coming off of the battery (put there by the previous owner) that powers the stereo. I teed a 12 gauge wire off of that 10 gauge wire and ran it back to that relay. The relay only powers the fuel pump, the fuse is for both. The rest of the wiring is exactly as shown in the diagram.
Old 06-22-14, 08:57 AM
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I have a saying at work "Never trust anyones connections or terminations".

With that said, a 30 amp relay on a 30 amp fuse that isn't blown should not be getting hot. If it was pulling that much current, your 30 amp fuse would pop, so something else is wrong here.
Old 06-22-14, 12:20 PM
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After looking everything over again, I think the fuse holder is bad. I unplugged the fuse instead of disconnecting the battery to test all of my connections and I was still getting voltage at the pump. I'm going to replace the fuse holder and test everything again.
Old 06-23-14, 08:07 AM
  #47  
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Originally Posted by redheddude222
After looking everything over again, I think the fuse holder is bad. I unplugged the fuse instead of disconnecting the battery to test all of my connections and I was still getting voltage at the pump. I'm going to replace the fuse holder and test everything again.

See, this is why you never trust anyone else's termination or connections.
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