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View Full Version : Going back to EFI, question about fuel pump. .

FC Zach
03-31-2015, 12:52 AM
So after having my car set-up for carburetion since 2005 I had decided it was time for something new and that I wanted to go back to fuel injection, I'll be running the engine via a Sprint RE/Ludwig harness so no OE harness is present (was pulled years ago). I have reversed a lot of things I had done to the car in the past like pulling out wiring I made for the ignition, fan, fuel pump and what not. .

I'm trying to keep things simple and want the fuel pump to run off the original wiring (i had it hard wired to an open spot in the fuse block). I have reversed the hard wiring and reattached the pump wire (the blue one with yellowish stripe) back to the harness by the fuse box.

My question is, will I need to do anything else to the harness under the dash (there isn't one in the engine bay) to supply power to the pump? I believe there is a relay by the steering column for the fuel pump, not positive though. Terrible pic but this is what I saw in my manual, I think it says "fuel injection circuit opening relay"
http://www.2carpros.com/forum/automotive_pictures/12900_cor_4.jpg

Also, is this something I will have to have?
http://i5.photobucket.com/albums/y194/swilton75/FC3%20Mazda%20RX7/P1010465.jpg

If those things are necessary I may just hard wire the pump again, any suggestions?

Thanks in advance, Zach
TitaniumTT
03-31-2015, 01:09 AM
You should hard wire the pump anyway.... I would run some good 14ga wire from the battery ( both hot and grnd) to a relay and use the trigger of the haltech to trigger the relay to power the pump.... Which fuel pump are you using?
That dohickey you posted the pic of looks like the fuel pump relay resistor.... Varies pump speed and useless shit like that
FC Zach
03-31-2015, 01:32 AM
Thanks Brian! Yeah I think I'll just run some new wire to and from a relay because after seeing the resistor assy. from my searching I started to change my mind on trying to utilize the OE wiring.

I'm running an OE pump, not sure what series it is if there is even a difference. I got it from My5ababy a few years ago.
TitaniumTT
03-31-2015, 02:04 AM
Cheers Zack! Yeah, no need to utilize all the stock wiring when it's not necessary.... I remember I put a haltech in a bone stock TII and what I did was use parts of the stock harness and wired the haltech trigger to the factory connector by the blower motor, eliminated the resistor but jumped the wires, hooked up a toggle switch to the relay under the dash to make it a cutoff switch and just ran some marine duplex back to a new relay. Used what was once the stock fuel pump power wire to activate the new relay and bam! Consistent fuel pressure :awesome:
FerociousP
03-31-2015, 08:45 AM
You should hard wire the pump anyway.... I would run some good 14ga wire from the battery ( both hot and grnd) to a relay and use the trigger of the haltech to trigger the relay to power the pump.... Which fuel pump are you using?
That dohickey you posted the pic of looks like the fuel pump relay resistor.... Varies pump speed and useless shit like that

^this. fresh wire from a triggered relay (probably in your ludwig harness already).
FC Zach
03-31-2015, 08:57 AM
^ True, I emailed Chris to see. My guess is that you're right Paul.
infernosg
03-31-2015, 10:14 AM
If Chris builds yours any way like he did mine you'll have a dedicated output for fuel pump power. So glad I had him make the harness!
FC Zach
03-31-2015, 10:35 AM
Sweet, Thanks!
FC Zach
03-31-2015, 12:54 PM
Just got the answer I needed to hear, the fuse box will have wiring for the pump! :driving: