EFI / COIL wire voltage help needed.

[livetobefree1965]

Hello everyone, I sure could use some advice on how to figure out why I lose battery voltage on the EFI/COIL wire with the ign switch in the start position. I'm assuming it is meant to supply current to the coil as I don't have EFI. What is odd to me is that it has battery voltage in all switch positions except off and start. If I'm barking up the wrong tree with this wire, which wire is used to power the coil. Thanks for your help with this issue as I'm almost ready for first start (and I will run a wire direct from the battery to the coil) lol. You guys have been a world of help with this build already but I've had no luck in trying to find an answer to this issue searching other posts.

Thanks!
Donis

[Jeff Kleiner]

What you’re seeing is normal. The light blue “EFI CRANK POWER” is energized in when the ignition switch is in the start position then when you turn back to the run position it drops out and the “EFI/COIL” wires is energized.

Jeff

[phileas_fogg]

I think perhaps Jeff misspoke, or I'm reading his description incorrectly. Your orange EFI/COIL wire should be hot at both RUN and START (if it wasn't hot at START, then the EFI computer would power off). So if you don't have power on the orange wire at START, something is amiss.


John

[D Stand]

Looking through the wiring harness details it looks like you might have a miss wire at the ignition switch or the fuse panel. Your description of how this wire is acting is an “ACC” feed which is powered at run and turned back once from off. First test to see if you have power to the coil with the key turned back one to confirm. If yes, double check your ignition switch connections. If you mis-wired your ignition switch your turn signals, fuel pump and choke wire might be on with the key back one too. Also just to be clear, you are talking about the orange wire “EFI/COIL” right?

[rich grsc]

What you’re seeing is normal. The light blue “EFI CRANK POWER” is energized in when the ignition switch is in the start position then when you turn back to the run position it drops out and the “EFI/COIL” wires is energized.

Jeff

Jeff is correct, the EFI/coil wire is hot in the 'run' position, but not in start. This is a 'fall back' to when cars had points in the distributer. The coil had a resister to drop voltage to about 8v when the car was running, this prevented the points from pitting and burning out, how ever when starting you wanted a full 12v at the coil. This was done by having the switch apply full volts when in the crank or start position only.

[Papa]

When wiring my Sniper, I tested both the orange EFI/COIL wire and the blue EFI/Crank wires. The Sniper requires +12v in both the run and start ignition positions. The orange EFI/COIL wire satisfies that requirement, but the blue EFI/CRANK wire is only hot in the start position on the ignition. I used that orange wire to trigger a relay that provides power to my coil and EFI. The relay gets power via my bus bar that is fed directly from the battery.

[D Stand]

My orange EFI/COIL wire has 12volts on run and cranking

[michael everson]

I bet you have the ignition switch wired wrong. Check the IGN and ACC and see if you have them swapped. Orange coil wire has power while cranking

Mike

[RBachman]

I went through this a few times just Thursday...literally, and have installed 6 EFI throttle bodies (FiTech and Sniper). Sniper is superior and has actual customer/technical service. FiTech is.....lacking.

Make sure you follow the directions with the Sniper carefully and exactly. Also, CALL HOLLEY 1-866-464-6553! They are incredibly helpful, knowledgable and have extended tech service hours. The wait is often long, but well worth it. Exceptional Technical Service!!!!!

There is a requirement for direct battery connections, the schematic in the manual will show you how to connect the coil. HOWEVER, go to the Holley website and download the entire manual! https://www.holley.com/products/fuel_systems/fuel_injection/sniper_efi/sniper_efi_quadrajet/parts/550-869.

Also, READ everything. Pay special attention to the yellow wire. (Bad evil wire if not done properly). Also, make sure you have a full flow 10 micron fuel filter before the throttle body supply port. Then, ensure that you have good separation between the Sniper wires and any dirty voltage/current that may cause electrical interference (alternator wiring, coil wiring, motors, etc.) A rule of thumb is that if the wires come out of the TB together, they can run together, but do not wrap them up with coil or alternator wiring. Then, before you attempt to start the engine, go through the set-up procedure with the handheld.

[D Stand]

139519

See attached FFR ignition switch detailing function of each terminal. I bet you have the orange and brown swapped.

Thanks Dale

[livetobefree1965]

Thanks so much guys! I'll be checking what I have compared to all of your recommendations. I wired the ign switch very early on so it could be wired incorrectly. Will check it. The EFI crank wire is hot in the start position. The EFI/COIL wire is hot in the ACC and run position. I do know that the coil shouldn't be energized unless the engine is running as in the ACC position. By the way, I have a ready-to-run MSD distributor and coil set-up. No MSD box.

Thanks
Donis

[Papa]

If you find your ignition is properly wired, be aware there have been a few examples of incorrectly manufactured switches. You may want to test it also.

[RBachman]

If you find your ignition is properly wired, be aware there have been a few examples of incorrectly manufactured switches. You may want to test it also.

I had issues with mine also, but it was "loose" inside and tended to stay on when the key was removed unless I jiggled the key a bit as I pulled it out. I ordered a much improved switch from Forte's to correct that. Also, the FFR supplied switch has soft threads, so be careful when tightening the connectors so the screws don't strip out.

[livetobefree1965]

WOW!! That pesky orange wire! How did it get under that acc screw?? The wife must have put it there! LOL!!
On her behalf, Thanks guys! You all are life savers.

Donis

[D Stand]

Glad it was a simple fix.. Now go fire it off!