Holley Sniper EFI Planning and Installation

I'm anxiously awaiting delivery of my new Holley Sniper EFI, en route from Wild Horses! What follows will hopefully result in a successful installation (and not the aftermath of a massive fire.) The goal here is to eliminate the hot start issues, excessive fuel smell, flooding in off-camber situations and overheating that I've been battling over the last 13 years with an Edelbrock carb. Eventually I'd like this system to control timing as well.

For starters, I have been reading as much as I can about running the fuel lines. There's a lot of useful info in Ol'Blue's install thread, which let me to this thread about fuel pumps and this one about fuel lines. I'm still a bit fuzzy on best practices and hope to get some advice based on your experience.
Here's the current plan:
- I have the 23 gallon NWMP rear tank, with no aux tank, and have purchased the Bosch 69100 in-line pump. There are a lot of people who swear that an in-tank pump is the only way to go, but others seem to have had good luck with in-line setups. I'm willing to gamble on the in-line pump for $75 vs $600 for a new tank with an internal pump. This can always be changed later, but for now that is the plan.
- Looking to go low-pressure flex hose with clamps from the tank to the first filter, then to the pump. After the pump would be some sort of EFI flex line, like Earl's or Gates with the proper EFI-style clamps to the second filter, then to 3/8" steel hard line.
- Here's where I'm stumped option-wise. For the connection between the EFI flex and the steel hard line, I've read mixed reviews about using -6 AN fittings vs bubble flares & clamps. Is there a compelling reason to go one route vs the other? Clamps would be less expensive, but would it be considered unsafe? I have a friend who works in aviation. He has access to a quality 37-degree flaring tool and the experience to install AN fittings.
- Any tips to running the hard line? Best to stay outside the frame rail, using rubber-coated clamps every 18 inches or so to secure the line to the frame? Should the hard line stop at the frame near the front fender well, or would there be any benefit (or drawback) to running it up the firewall as well?
- For the return, I'd like to come back the same route and method as the supply line, but tee into the vent line next to the filler neck instead of installing a bulkhead fitting like the one that Holley supplies with their install kit (which I did not purchase.) Does anyone have experience doing this with their return?

If you have pics of how your fuel lines were run, or links to other threads that illustrate a quality install, I'd appreciate it.

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Hey cooter, I'm still undecided on which fittings and hose to change to but I will keep my hard line and the way I routed it because its far enough away from the exhaust and high up against the body. The hard line starts just after the fuel pump and 90's up along the top of the passenger frame rail, mounted up against the body where the cross members are located. I was able to bend it to match contour of the top side of the fender well at the firewall. Then Hose to the filter and then 45* An fitting to the EFI. The return line is low pressure line and follows the same path.

Not saying this is the best way to run things and will be following this thread for any recommendations.

I plan to change the Hose and may decide based on feedback you get here.

In the little bit of checking I did, it sounds like your nwmp tank should have a return port. Any reason why you wouldn't use it?

Also, for me routing the fuel lines was easier then figuring out how to run the wiring, relays, O2 cable etc.


Good luck and will be following.

Ol'Blue said:

Hey cooter, I'm still undecided on which fittings and hose to change to but I will keep my hard line and the way I routed it because its far enough away from the exhaust and high up against the body. The hard line starts just after the fuel pump and 90's up along the top of the passenger frame rail, mounted up against the body where the cross members are located. I was able to bend it to match contour of the top side of the fender well at the firewall. Then Hose to the filter and then 45* An fitting to the EFI. The return line is low pressure line and follows the same path.

Not saying this is the best way to run things and will be following this thread for any recommendations.

I plan to change the Hose and may decide based on feedback you get here.

Click to expand...

What hose are you running now and why do you want to change it?

Ol'Blue said:

In the little bit of checking I did, it sounds like your nwmp tank should have a return port. Any reason why you wouldn't use it?

Click to expand...

Good question. The tank I have looks just like the one on the WH website:

It has two fittings to the left of the filler neck. These tie in to the charcoal canister(?) and that tank that's nestled in the bed rail, right behind the driver's seat. My understanding is that these are too small for the return line, which should be a minimum of 5/16". To the right of the filler neck is the vent line. The description on WH website mentions an EFI return line, but that may be a newer version of the tank?? When I spoke with someone at WH, he said most people tie in to the vent line. I'm curious if I could ditch the emissions stuff with EFI, and possibly use one of those fittings for the return.

Ol'Blue said:

Also, for me routing the fuel lines was easier then figuring out how to run the wiring, relays, O2 cable etc.

Click to expand...

Oh boy! Hoping my avionics buddy will be able to help me out with this.

Thanks!

Cooter_76 said:

What hose are you running now and why do you want to change it?


Good question. The tank I have looks just like the one on the WH website:

It has two fittings to the left of the filler neck. These tie in to the charcoal canister(?) and that tank that's nestled in the bed rail, right behind the driver's seat. My understanding is that these are too small for the return line, which should be a minimum of 5/16". To the right of the filler neck is the vent line. The description on WH website mentions an EFI return line, but that may be a newer version of the tank?? When I spoke with someone at WH, he said most people tie in to the vent line. I'm curious if I could ditch the emissions stuff with EFI, and possibly use one of those fittings for the return.

The PO ditched my canister, so Im using one port as a vent and one for return. I would research the plumbing for the canister and us it if you can.


Oh boy! Hoping my avionics buddy will be able to help me out with this.

Thanks!

Click to expand...

Im running standard EFI hose with clamps lightly tightened on the barbed fittings. I may change to the type of hose that doesnt require clamps. Cant think of the type of hose... OR I may change my barbed fittings to vapor guard type that dont have the barbs and use clamps.

https://www.holley.com/products/plu...r_guard/vapor_guard_hose_ends/parts/750166ERL


The PO ditched my canister, so Im using one port as a vent and one for return. I would research the plumbing for the canister and us it if you can.

I spoke with someone from Holley's tech support line this afternoon. He said as long as you have a flare or knurl at the end of the steel hard line, you can just use the EFI-specific clamps for the Vapor Guard flex line. AN fittings & couplers would be overkill.
I also asked about the return line. He said a lot of people tie in to the vent or the filler neck, but cautioned against just allowing the return fuel to dump on top of the fuel in the tank. Apparently it will foam/aerate. Not sure how big a concern this is or how to go about preventing it without using a separate bulkhead connection and fuel cuff.

Cooter_76 said:

I spoke with someone from Holley's tech support line this afternoon. He said as long as you have a flare or knurl at the end of the steel hard line, you can just use the EFI-specific clamps for the Vapor Guard flex line. AN fittings & couplers would be overkill.
I also asked about the return line. He said a lot of people tie in to the vent or the filler neck, but cautioned against just allowing the return fuel to dump on top of the fuel in the tank. Apparently it will foam/aerate. Not sure how big a concern this is or how to go about preventing it without using a separate bulkhead connection and fuel cuff.

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Thanks for the feedback Cooter. I ended up ordering all new vapor guard hose ends yesterday. The type with just a flair at the end and not several barbs. A little piece of mind. I haven't had issues with aeration, hard to imagine that a little bit of fuel return could create that much of an issue. Will keep driving and see if issues arise.

Pretty stoked about my pick-n-pull score this morning! I snagged the HP fuel pump bracket off a mid-80's F150 for $3.70. Fits the Bosch pump like a glove.






I also grabbed a coolant/windshield washer tank for $5.80!

Mark,
AN fittings aren't necessary. Use FI rated soft hose, FI hose clamps and hard lines. Mine is long hard lines with shorter soft line connectors clamped tight with FI clamps. Your frame mounted fuel pump will work fine in that clamp thing wrapped in foam but be sure to mount it away from heat sources. Mine was mounted on cross member above rear diff between duel exhausts and it overheated. Mounted on a frame rail near fuel tank is good.
But before you install too many items because I'm not familiar with the FI system you ordered, reading the instructions is mandatory to see if they recommend something different than what I've recommended.
What are the stamps on those two outlets on your tank on the left of the filler neck. One of those can probably be used for return line. Might be worth a call to either the tank mfg or a Bronco vendor who sells them. Mine is a BCB tank and return line is located like those two on yours. Returned fuel does not aerate the fuel in the tank. Never heard that before. Many who don't have extra outlets connect return line to filler neck. Dump the charcoal canister. It's way past being effective unless you changed it probably 5 times since your EB was built.
JW in SA

I've decided to place the HP pump on the inside of the passenger side frame rail, behind the muffler. After a spirited drive the other day, I crawled underneath and this seemed to be a relatively cool place. I'll run the hard lines over and down the outside of the frame rail, to the firewall. The driver side frame rail has a brake line running down it, along with the wiring harness for the tail lights & tank sender, which would make it tough to mount the pump there. The passenger side should also make it easier to run the fuel lines up the firewall.
I'm still open to ideas for where to tie the return line into the tank.

Holley sells a bulkhead fitting to go into tank just above filler in front if stock tank, if you have any room try for top. As noted, return lines do not need AN or hi pressure anything just fuel rated hose.

I have dropped some dime, bought an EFI sherman tank tank today.

I have looked the look and still favoring Holley above all else with this problem: 2 month backlog. Fitech I can have today, in fact everyone has them, which tells me something..... If I step up a notch I can get the Holley Stealth but thats a pricey step.

Finally started making a little progress.
First step was to pull the carb, fuel pump and all the old fuel lines (including unused lines and wires for the old aux tank.) Second step was to clean 2 lbs of dirt out of my eyes and go find some better safety glasses.



In comparing the linkages on the Edelbrock vs the Holley I realized there was no way to hook up the kickdown rod for the C4. I called Holley, who said they are working on a solution, but don't have an ETA. Thanks to this site, I found out I can use this kickdown cable from BC Broncos, which should arrive tomorrow.

I had some time this morning and decided to install the O2 sensor. Nothing's ever simple. After drilling a hole in the passenger exhaust pipe, I tried to mount the strap-on bung hole that comes with the Sniper kit, but the clamp broke before it got tight enough.




Instead of going out to get another clamp, I figured I might as well just take the exhaust pipe to a local muffler shop and have a bung welded-in for $45.

73azbronco said:

Holley sells a bulkhead fitting to go into tank just above filler in front if stock tank, if you have any room try for top. As noted, return lines do not need AN or hi pressure anything just fuel rated hose.

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I've thought about that, but I'd prefer not to have to drop my tank and drill a hole in it.

73azbronco said:

I have looked the look and still favoring Holley above all else with this problem: 2 month backlog. Fitech I can have today, in fact everyone has them, which tells me something..... If I step up a notch I can get the Holley Stealth but thats a pricey step.

Click to expand...

I think I got the last one that Wild Horses had in stock, which is how I wound up with the gold finish. I probably would have gone with black if given the choice, but now that I see the gold in person I kinda like it.

I liked the gold as well. But.... The black is cool .....

73azbronco said:

I liked the gold as well. But.... The black is cool .....

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I'll sell you a gold one for $2500. Free shipping! ;D

Spent some time this morning installing the BC Broncos kickdown cable. Installation at the transmission was pretty straight-forward, using the brackets and instructions from BC.
Holley supplies some brackets to connect a throttle cable and kickdown cable with the Sniper kit. I'm using the factory throttle linkage, though, and the Holley bracket interferes with this.


A little chopping and drilling allowed me to flip the bracket upside down to gain clearance.


I'm sure there's a thread somewhere on this site that discusses how to properly setup and adjust the kickdown cable at the throttle body, but I'll save that for later.

Cooter_76 said:

Spent some time this morning installing the BC Broncos kickdown cable. Installation at the transmission was pretty straight-forward, using the brackets and instructions from BC.
Holley supplies some brackets to connect a throttle cable and kickdown cable with the Sniper kit. I'm using the factory throttle linkage, though, and the Holley bracket interferes with this.

A little chopping and drilling allowed me to flip the bracket upside down to gain clearance.

I'm sure there's a thread somewhere on this site that discusses how to properly setup and adjust the kickdown cable at the throttle body, but I'll save that for later.

Click to expand...

Looking great Cooter! Did you have any issues with the kick down interfering with the valve cover? I did with my Lokar kick down, and ended up having to install a spacer under the throttle body.

Making good progress. I like your f.p. mounting location and your o2 sensor is up and out of the way. Almost Roundup time.

My EFI's been installed for 9 yrs and I've never installed a kick down cable. Bought the BCB cable way back when and it's still in the box on the shelf. Needing a lower gear to accelerate just requires a pull down one notch on the column shifter which to me is just as good as doing it with the skinny pedal. If I drove it more on highways etc maybe installing the cable would be better.

Connect the return line to one of those two outlets in front of the filler tube. Probably why they're there.

jw0747 said:

Making good progress. I like your f.p. mounting location and your o2 sensor is up and out of the way. Almost Roundup time.

My EFI's been installed for 9 yrs and I've never installed a kick down cable. Bought the BCB cable way back when and it's still in the box on the shelf. Needing a lower gear to accelerate just requires a pull down one notch on the column shifter which to me is just as good as doing it with the skinny pedal. If I drove it more on highways etc maybe installing the cable would be better.

Connect the return line to one of those two outlets in front of the filler tube. Probably why they're there.

Click to expand...

Thanks. My goal is to get it up & running by the end of next week so I have a couple of weeks to trouble-shoot and tune before Round Up. I'll try to stay out of the mud this year. ;D