Holley Sniper EFI on 401

For everything related to using Fuel Injection in an FSJ.

Topic author
KJ Ryu
Posts: 993
Joined: Sun Jun 10, 2012 8:03 am
Location: Casper

Re: Holley Sniper EFI on 401

Post by KJ Ryu »

I didn't take a lot of pics but, here's a link to my postimage folder: https://postimg.org/gallery/172qyktsk/
Ron

2005 KJ, Hit-n-Run, 2am 6-17-2012, Totaled. :mad:
1977 SJ J10, 4v360, T18, D20, 37x14s, SOA & SF on tons, still ugly.
1978 SJ Wagoneer, 4v360, QT, 33x12.5s, lift by Sawzall :-bd NOT Running :(
1977 SJ J10, SniperEFI 401, QT, D44s, 31X10.5s :fsj:
2006 KJ
Mars wrote:One man's trans leak is another's penetrating oil :D
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az chip
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Joined: Tue Jul 14, 2015 8:59 pm
Location: Mesa, AZ

Re: Holley Sniper EFI on 401

Post by az chip »

Would not let me see pics.
'81 Cherokee Chief 81 WT Chief/MSD 6/Holley Sniper/ Rusty 4" Spring lift/ Bulltear oil adapter/K&P Engineering Oil Filter/ NP 208/ Serehill Light Harness/KC LED Headlights/ Evil Twin Fab Roof Rack and sliders/ Ross mirror mounts.

Topic author
KJ Ryu
Posts: 993
Joined: Sun Jun 10, 2012 8:03 am
Location: Casper

Re: Holley Sniper EFI on 401

Post by KJ Ryu »

Let me know if this works for you.

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Ron

2005 KJ, Hit-n-Run, 2am 6-17-2012, Totaled. :mad:
1977 SJ J10, 4v360, T18, D20, 37x14s, SOA & SF on tons, still ugly.
1978 SJ Wagoneer, 4v360, QT, 33x12.5s, lift by Sawzall :-bd NOT Running :(
1977 SJ J10, SniperEFI 401, QT, D44s, 31X10.5s :fsj:
2006 KJ
Mars wrote:One man's trans leak is another's penetrating oil :D
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az chip
Posts: 1433
Joined: Tue Jul 14, 2015 8:59 pm
Location: Mesa, AZ

Re: Holley Sniper EFI on 401

Post by az chip »

Thanks for doing that. Those I see fine.
'81 Cherokee Chief 81 WT Chief/MSD 6/Holley Sniper/ Rusty 4" Spring lift/ Bulltear oil adapter/K&P Engineering Oil Filter/ NP 208/ Serehill Light Harness/KC LED Headlights/ Evil Twin Fab Roof Rack and sliders/ Ross mirror mounts.
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az chip
Posts: 1433
Joined: Tue Jul 14, 2015 8:59 pm
Location: Mesa, AZ

Re: Holley Sniper EFI on 401

Post by az chip »

What did you do with the PCV system?
'81 Cherokee Chief 81 WT Chief/MSD 6/Holley Sniper/ Rusty 4" Spring lift/ Bulltear oil adapter/K&P Engineering Oil Filter/ NP 208/ Serehill Light Harness/KC LED Headlights/ Evil Twin Fab Roof Rack and sliders/ Ross mirror mounts.

Topic author
KJ Ryu
Posts: 993
Joined: Sun Jun 10, 2012 8:03 am
Location: Casper

Re: Holley Sniper EFI on 401

Post by KJ Ryu »

az chip wrote:What did you do with the PCV system?
Sorry for taking so long to reply. I didn't do anything with it. PO installed the intake manifold and mangled... err, I mean removed the emissions stuff. But, I'll get some pics and what-not asap (this weekend, probably). Not even sure it is correct, tbh.

On a positive side note, there was one good thing about ordering direct from Holley: I get a free t-shirt for writing a review!

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Ron

2005 KJ, Hit-n-Run, 2am 6-17-2012, Totaled. :mad:
1977 SJ J10, 4v360, T18, D20, 37x14s, SOA & SF on tons, still ugly.
1978 SJ Wagoneer, 4v360, QT, 33x12.5s, lift by Sawzall :-bd NOT Running :(
1977 SJ J10, SniperEFI 401, QT, D44s, 31X10.5s :fsj:
2006 KJ
Mars wrote:One man's trans leak is another's penetrating oil :D

posulli88
Posts: 18
Joined: Thu Dec 15, 2016 7:49 pm

Re: Holley Sniper EFI on 401

Post by posulli88 »

What did you end up using for your 12v source (hot with ign on and cranking)? Installing mine this weekend and its the only part I am struggling with to find. Thanks!

Topic author
KJ Ryu
Posts: 993
Joined: Sun Jun 10, 2012 8:03 am
Location: Casper

Re: Holley Sniper EFI on 401

Post by KJ Ryu »

I used a red wire with a white trace on it. I thought it went to the electric choke but, looking at the diagram on oljeep, it seems to be the coil+. Someday, I may need to rewire the whole thing, so I know for sure.

The PCV valve is plumbed directly to manifold vacuum, at the base of the throttle body. Like I said, probably not right but that's how it was before I got it.
Ron

2005 KJ, Hit-n-Run, 2am 6-17-2012, Totaled. :mad:
1977 SJ J10, 4v360, T18, D20, 37x14s, SOA & SF on tons, still ugly.
1978 SJ Wagoneer, 4v360, QT, 33x12.5s, lift by Sawzall :-bd NOT Running :(
1977 SJ J10, SniperEFI 401, QT, D44s, 31X10.5s :fsj:
2006 KJ
Mars wrote:One man's trans leak is another's penetrating oil :D

FSBOB
Posts: 23
Joined: Fri Jun 23, 2017 6:30 pm
Location: Minnesota

Re: Holley Sniper EFI on 401

Post by FSBOB »

I know I'm a couple months late on this thread but if you're looking to rewire your truck think about contacting Z & M Jeep. He's got new wiring harnesses specifically for 79 J-Trucks. The only thing I found that wouldn't work in my 76 was the washer fluid and wiper wires. In 79 they ran the hot wires to the switch and grounded through the wipers/fluid pump. Previous to 79 it's opposite. A little reverse engineering on that one issue and all of the wiring in my truck is brand new and working great. Did cost somewhere in the range of 1k though.... Just something to think about when you get to that place.
1976 Jeep J20 401, T15, Dana 20, Holley Sniper EFI, Hedman Headers, MSD Ready-to-Run Ignition, 33" Cooper MTP's :fsj:

Topic author
KJ Ryu
Posts: 993
Joined: Sun Jun 10, 2012 8:03 am
Location: Casper

Re: Holley Sniper EFI on 401

Post by KJ Ryu »

Small update: I installed a progressive link on my Sniper, yesterday. At the same time, I also replaced the filler hose. When I did that, I realized how much better my mileage has gotten, as a LOT of gas came out when I unhooked the old hose even though I've driven it quite a bit since the last fill up.

My handheld display needed updated but the EFI's ECU did not. The truck is definitely easier to accelerate from a stop and reacts very nicely when the secondaries open up. This is what I was originally expecting from EFI. Very happy with this system now!

I got a much nicer looking bend than the one in the instructional video, too.

Image
Ron

2005 KJ, Hit-n-Run, 2am 6-17-2012, Totaled. :mad:
1977 SJ J10, 4v360, T18, D20, 37x14s, SOA & SF on tons, still ugly.
1978 SJ Wagoneer, 4v360, QT, 33x12.5s, lift by Sawzall :-bd NOT Running :(
1977 SJ J10, SniperEFI 401, QT, D44s, 31X10.5s :fsj:
2006 KJ
Mars wrote:One man's trans leak is another's penetrating oil :D

Jeepin87
Posts: 14
Joined: Mon Jan 28, 2013 12:31 am

Re: Holley Sniper EFI on 401

Post by Jeepin87 »

KJ Ryu wrote:Small update: I installed a progressive link on my Sniper, yesterday. At the same time, I also replaced the filler hose. When I did that, I realized how much better my mileage has gotten, as a LOT of gas came out when I unhooked the old hose even though I've driven it quite a bit since the last fill up.

My handheld display needed updated but the EFI's ECU did not. The truck is definitely easier to accelerate from a stop and reacts very nicely when the secondaries open up. This is what I was originally expecting from EFI. Very happy with this system now!

I got a much nicer looking bend than the one in the instructional video, too.

Image

Are you referring to a progressive link on the throttle? If so I've been trying to figure out what is required for this, I don't like how all 4 butterflies open at once. I would expect more linear throttle input and possibly better mpg as well. Please share part numbers and software/parameter changes if possible!

Topic author
KJ Ryu
Posts: 993
Joined: Sun Jun 10, 2012 8:03 am
Location: Casper

Re: Holley Sniper EFI on 401

Post by KJ Ryu »

https://www.efisystempro.com/sniper/sni ... inkage-kit

This company includes a copy of the instructions with each linkage, as well as having it on their website. I had to update my handheld display but the TBI's ECU was ready to go.
Ron

2005 KJ, Hit-n-Run, 2am 6-17-2012, Totaled. :mad:
1977 SJ J10, 4v360, T18, D20, 37x14s, SOA & SF on tons, still ugly.
1978 SJ Wagoneer, 4v360, QT, 33x12.5s, lift by Sawzall :-bd NOT Running :(
1977 SJ J10, SniperEFI 401, QT, D44s, 31X10.5s :fsj:
2006 KJ
Mars wrote:One man's trans leak is another's penetrating oil :D
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Moosehead
Posts: 41
Joined: Wed Jun 20, 2018 9:13 pm
Location: Mountain West

Holley Sniper EFI on 401

Post by Moosehead »

Installed the adjustable EFI System pro progressive link this morning. Getting the OEM cotter pin out was a bit tricky so removed the Sniper TB to make it easier to remove original.

Note EFIP recommends starting the adjustable progressive link on its shortest setting, but in my setup that caused the secondary butterfies to hold open a bit putting idle RPM’s at 3900. I backed it off so both linkages stayed in same static start position and she purred like a kitten. The progressive throttle is much nicer for daily driving though you need to get on the pedal to beat old ladies at the stoplight.

Adjustable link at shortest setting keeps secondary TB open a bit:

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Backing off a bit so both linkages unaffected at zero throttle:

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Butterflies fully closed at no throttle with adjustment backed out a bit.

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‘78 Wagoneer
401 with street cam, heads, headers, Holley Sniper EFI, rear discs, Alcan springs, Trucklite LED headlights
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