EFI wiring and engine hookups - check my work

[mladen]

Hey all,

So while I wait for some cooling-related parts, thought I'd take a stab at figuring out how to wire everything around the engine. As a reminder, I have a 351w based BPE with Sniper EFI, Vintage gauges, RF harness. I have to say this was quite daunting. The Wiring harness manual has literally just 4 lines of text when it comes to wiring the EFI. BPE mostly gives you the instructions for the parts. I ended up mainly using the long-form (https://documents.holley.com/199r11031r.pdf) Sniper Instructions, but the BPE wiring supplement was helpful. Here is what I'm planning so far:

These are the relevant wires from the RF harness going into my engine compartment:
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7-Pin Connector:
- Red > Battery (+)
- Black > Battery (-)
- Blue > Orange fuel pump relay wire in RF harness
- Violet > n/a
- Dark Green > n/a
- Yellow > Coil (-)
- Pink > Tan Electric Choke wire in RF harness. I was too hasty when plumbing the harness and removed this wire thinking I won't need it. I need to re-pin into the connector and wire it through

10-Pin Connector. This is where I'm more uncertain. Sniper instructions above talk about two setups, timed and not timed. Since the supplement says "At BluePrint Engines, we do NOT enable timing control" I'm assuming what I have is non-timed, so I based this on the second picture on page 22 of the instructions linked above:
- Orange > n/a
- Yellow > n/a
- Light Blue > RF Green Fan wire
- Light Green > n/a
- Gray > n/a
- White > n/a
- Dark Brown > Purple Coil->Tach wire in RF harness?
- Tan > n/a

Questions:
1. Does the plan for the 7-pin connector wires look good?
2. Does the plan for the 7-pin connector wires look good? And am I right about Dark brown going to the purple Coil->Tach wire?
3. Now, the Coil is said to also need keyed 12v+ power. Can I use either the Orange Coil or EFI, or the Light Blue EFI Crank Power wire from the RF harness for this? In either case, do I even need these otherwise? I'm not sure where they would connect to.
4. Do I need to connect the Green and Gray wires for Speedo to anything, given I have GPS gauges?
5. Is this plugged bung where I would connect an oil pressure sensor?
6. There is a short gray wire on the distributor. What should that be connected to?

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7. If I wanted to connect an oil temp sensor, would this side bung on the oil pan be a good place for it (there's a drain on the rear side)?

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8. Random question. What's this metal tray in front of the Sniper? I'm assuming it is NOT for putting your coffee while you work on the engine :) My best guess is that it helps isolate the EFI electronics from potential interference from the distributor

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[Papa]

What ignition setup do you have? That will make a difference on how to wire things. If you have a standard distributor and coil (no Hyperspark, DualSync, CDI box, etc), then what you've described is good. You may find that the tack wire is easier to run directly from the coil, which is what I did, but the tach wire from the Sniper should also work.

Don't use the blue EFI Crank Power to power your coil. The orange EFI/Coil wire is what you want.

Nothing to the speedo except the GPS antenna and wires for the lights.

Yes on the oil pressure sender location.

The short gray wire on the distributor can be used as a tach signal.

The bung on the oil pan would be used for an oil temp sender.

I've never seen the tray, but assume that is an RFI shield as you suspect.

[mladen]

Dang, deleted my reply by mistake. Here it is again:

Thanks for the reply, Papa! Good question on the distributor. I'm not really sure how to tell. BPE page doesn't specify, nor do any of the documents I've gotten from them. I can call tomorrow to ask them. Here is how the setup looks and the only markings I could find

The page (https://www.holley.com/products/ignition/distributors/ford/parts/83541) for that model under Type lists "Ready To Run", and also that it doesn't require an MSD Ignition Control.

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Only additional devices I got in the kit from BPE are the 3" LCD for programming the EFI, and this Ignition Coil Driver

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which makes me think maybe my setup is more like the first images on pages 29 or 35. But those do not show the coil connected to the distributor, which mine definitely is, like show on page 25, and in the installation manual for MSD 83541. What I have in the engine now definitely looks like Figure 13 on page 7 here (https://documents.holley.com/frm30245_8350_8354_8352_83503_83523_835231_835251_ 0219.pdf)

But to summarize your other points about the wires. Sounds like I can power the coil with the Orange `EFI or Coil` wire, and remove the Green and Gray speedo wires, as well as the Light Blue EFI Crank Power wire.

[Norm B]

That is a ready to run distributor and there is no allowance for external timing control. It connects to the coil for its power source and ignition control. The coil driver is not used with this distributor. Keep it in case you decide to change to the Hyperspark or Dual Sync distributors that allow the Sniper to control the timing and don't want to use an ignition box.
The tray must be an attempt to control RF interference. May or may not work depending on your air cleaner choice. The Sniper unit is very sensitive to loose electrons under the hood.

Norm

[Nigel Allen]

That is a ready to run distributor and there is no allowance for external timing control. It connects to the coil for its power source and ignition control. The coil driver is not used with this distributor. Keep it in case you decide to change to the Hyperspark or Dual Sync distributors that allow the Sniper to control the timing and don't want to use an ignition box.
The tray must be an attempt to control RF interference. May or may not work depending on your air cleaner choice. The Sniper unit is very sensitive to loose electrons under the hood.

Norm

"Loose electrons" - I love it ;)

[Papa]

Sounds like the "standard" ignition, so it should be good to go. I also recommend de-pinning the Sniper wires that won't be used in your setup. Holley sells a de-pinning kit that includes the tool and silicone plugs for the empty pin ports in the connector.

https://www.summitracing.com/parts/hly-567-101

De-pinning will help with RFI, as all the loose wires can act as antennae.

[mladen]

Ok. I have one more question.

I de-pinned the 10-pin connector. Looks funny with just one wire in it, but I don't want to but the cable comming out of the Sniper. In case I need to change the wiring I can just re-pin the connector. I even saved the original wires and pins. I do need to add the plugs (https://smile.amazon.com/gp/product/B00NVJ00AW/ref=ppx_yo_dt_b_asin_title_o00_s01?ie=UTF8&psc=1) into it, waiting for them to arrive.
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The question I have is about the 7-pin connector. I know I have to remove the purple and green wires. But it also has the large blu wire and relay to go to the pump. Since I'm not going to do that, planning just to splice into the RF harness, can I remove the relay, the thick blue wire, and just connect the thin blue wire to the RF relay? Want to make sure before I start slicing and dicing this nice harness.

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[Papa]

I don't recommend removing the fuel pump relay. If you do, the signal coming from the Sniper will be a ground signal. This will require tying into the ground side of the RF harness. No big deal, but you just need to be aware of the difference.

[mladen]

Thanks! I was going of off this part of the instructions, and mainly thinking to avoid a relay controlling a relay. The other reason being that I already routed and buttoned up everything to the rear and would hate to have to undo it all to thread the blue Sniper wire through.

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[Papa]

Thanks! I was going of off this part of the instructions, and mainly thinking to avoid a relay controlling a relay. The other reason being that I already routed and buttoned up everything to the rear and would hate to have to undo it all to thread the blue Sniper wire through.

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I made the connection where the rear harness connects to the main harness behind the dash. I de-pinned the tan fuel pump wire from the rear harness connector and connected the dark blue wire directly to the fuel pump wire using a separete weatherpack connector.

https://thefactoryfiveforum.com/attachment.php?attachmentid=92581&d=1536020966

This eliminates the need to cut anything at the fuse block. It does mean that you need to reconfigure the inertia switch.

[mladen]

Got it. Looks like the three options are:

1. Run Sniper harness intact and splice the thick Blue (12+) wire into the orange wire on the pump relay in RF Harness. Preserves existing inertia switch functionality. No messing with the Sniper wire, but using two relays
2. Remove the relay and thick Blue wire from the Sniper harness, run only the thin Blue wire (-) and connect to the side of the inertia switch that is usually going to the ground. Removes the extra relay from the harness, preserves the rest of RF wiring
3. Run the thick Blue (12+) wire behind the dash, from there connect it directly to the tan wire going to the fuel pump. Uses the Sniper relay, no changes to the fuse panel. Inertia switch needs to be rewired in order to work

[Norm B]

I sort of used your option 2 and it works flawlessly.
Being in Canada means we can only import a "starter kit". We are not allowed to import any electrical, suspension, fuel or brake components with the kit. I used an American Autowire 12 circuit system to wire my car. The fuel pump relay is included in the harness and I used the small blue wire from the Sniper fuel pump relay as the ground trigger. I put a hidden switch in the ground wire for theft prevention and maintenance purposes.
The Sniper fuel pump relay was repurposed.

Norm

[mladen]

I'm leaning in that direction too. While I'd like to not modify the Sniper harness, I less like the option of their relay dangling in the engine compartment.

There is a 4th option of just running the thick blue wire directly to the pump. I also read comments in the other threads about the thick blue wire being thicker than the tan one in the RF harness, as a pro for that option, but that blue wire still gets powered through the relay from the pink wire, which is pretty thin, so doesn't make too much difference.

[Norm B]

that blue wire still gets powered through the relay from the pink wire, which is pretty thin, so doesn't make too much difference.

Not quite true. If you break the harness down far enough you'll find a heavy red wire on the relay and that is connected to the heavy red wire that runs to the battery in the Sniper harness. This is the power feed wire and the pink wire is the + relay trigger wire.

Norm

[mladen]

Yup, you're right. It's even visible in my photo earlier.