Aftermarket Fuel System wiring (ignition)

[Angrey]

I'm planning a fuel system and have a question about the ignition source for the wiring harness(es).

Where does the typical aftermarket setup get it's ignition source? From the OEM harness?

The pumps I'll run have an internal check valve so the system should remain pressurized and primed upon turn off, but I'd like the pumps to "prime" but would also prefer they don't run and cycle fuel needlessly if the accessories/key is on but the car isn't running.

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[Angrey]

aftermarket kits come with a 4 or 6 gauge power wire that connects to your battery. It has either a controller or relays Connected to it for key on power..

Thanks, but that's not much help. I'm not using anyone of that. I have my own harness and my own fuel pump drivers. I'm asking if there's an appropriate "key on" wire/signal I can use to activate my pump controllers.

Interestingly, I'm wondering if the OEM feed line is big enough to run as a return (what is it 6 AN?). Could save me some time and money rather than plumbing a whole new line and fittings from the regulator.

And I'm not really a fan of the way they plumbed this, it'll look clean enough but I'm not keen on the regulator laying all weird and just flopping around underneath the intake tube/etc. With that VMP blower setup, it's probably more difficult to find a clean spot on the firewall or the shock tower, but just letting it flop around isn't my style.

 

[TGGT]

You can use the factory fuel pump + wire to trigger your relays. I’m using the factory feed as my return and it’s keeping up with my 2 walbro 465’s. Hope this helps

 

[Angrey]

You can use the factory fuel pump + wire to trigger your relays. I’m using the factory feed as my return and it’s keeping up with my 2 walbro 465’s. Hope this helps

Thanks,

I guess I'm going to have to meter test the wire harness for the ignition on and strip it and couple with my controllers.

I'm now planning on using the factory fuel line as my return line. I just wish someone could confirm that it's 3/8" (6AN equivalent). I'm planning to use the barb/lock adapter fittings like VMP does in the video. save me a little money on return line and I only need a 6 AN return.

 

[FastCarFanBoy]

Yellow/brown stripe on the FPDM plug is key on power and will prime just like stock.

I have seen people wire to the purple/green also but I think it will run the pumps whenever the key in on this way.

 

[TGGT]

Factory fuel line is 3/8

 

[Angrey]

Yellow/brown stripe on the FPDM plug is key on power and will prime just like stock.

I have seen people wire to the purple/green also but I think it will run the pumps whenever the key in on this way.

Muchas Gracias!

 

[Angrey]

Factory fuel line is 3/8

Thanks! So just to make it idiot proof, if I get fittings with a 3/8" pushlock barb, I can simply repurpose the factory fuel line to my return feed from the regulator and reuse the OEM connector at the front (off the rails) and at the back on the adapter at the new module?

 

[TGGT]

Thanks! So just to make it idiot proof, if I get fittings with a 3/8" pushlock barb, I can simply repurpose the factory fuel line to my return feed from the regulator and reuse the OEM connector at the front (off the rails) and at the back on the adapter at the new module?

Yes sir. That’s exactly what I did

 

[5.0_SD]

I have a bunch of electrical diagrams in my profile if that will help you.

 

[Angrey]

Resurrecting this thread. Check these out.

So it seems like I can use either the violet-green wire that comes into the FPDM and tap that as my ignition on, and it will either be off or 12V with the ignition on (including accessories).

Or, I can use the Yellow Grey wire which should give power under the same logic as the factory pumps (initial prime for a few seconds but don't run accessory on, full on when the pumps are running).

Is there any advantage or drawback to running either of those?

 

[Angrey]

Lethal Performance Tech Tips: Your fuel pumps get TRIGGERED! - YouTube

So Lethal does a great in depth write up. My question is, if I trigger between the FPDM and the OEM pumps, is that current pulsed? Or is it a full send? I thought the whole point of the FPDM was that it wasn't always full send. Will that affect the relays or is it a non-issue?

 

[illtal]

Lethal Performance Tech Tips: Your fuel pumps get TRIGGERED! - YouTube

So Lethal does a great in depth write up. My question is, if I trigger between the FPDM and the OEM pumps, is that current pulsed? Or is it a full send? I thought the whole point of the FPDM was that it wasn't always full send. Will that affect the relays or is it a non-issue?

No that signal is the pump enable signal: It is the same as when you walk up to the car and the pump turns on. I believe it is a yellow with grey tracer wire from the FPDM . The actual pump wire is thicker gauged wire. what pumps are you using? You can use the FPDM wire for one pump I believe as long as it doesn't exceed 25 amps.

 

[Angrey]

No that signal is the pump enable signal: It is the same as when you walk up to the car and the pump turns on. I believe it is a yellow with grey tracer wire from the FPDM . The actual pump wire is thicker gauged wire. what pumps are you using? You can use the FPDM wire for one pump I believe as long as it doesn't exceed 25 amps.

This is just for trigger(s). I'll have 3 (or 5 really). 2 Primary pumps, two passive lift pumps and an electronic regulator. I just need a good clean trigger source for when the system should operate and would prefer to stick to OEM logic (prime and key on, etc). Was just curious if that's pulsed. If not, we're good to go.

I have new power feeds for supplying everything with juice.

 

[illtal]

This is just for trigger(s). I'll have 3 (or 5 really). 2 Primary pumps, two passive lift pumps and an electronic regulator. I just need a good clean trigger source for when the system should operate and would prefer to stick to OEM logic (prime and key on, etc). Was just curious if that's pulsed. If not, we're good to go.

I have new power feeds for supplying everything with juice.

I got it. Those regulators used to finicky, a few revisions ago. Dunno how they are now though. I was thinking of doing a big surge so I can use whatever I wanted for pumps, but I found a way to PWM the Ti274 pumps I got outside of the factory module. Going to find out if keeping it simple is better in a month.

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