Sniper EFI Installed

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1979bettywhite
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Sniper EFI Installed

Post by 1979bettywhite »

So as some of you may have followed and know, my 360 went off to be reman'd a couple weeks ago and it is now back and in. At the same time I had the shop install the Sniper kit on it as well (4 barrel version as well as Edelbrock non-EGR intake). Running stock distributor and stock coil. They ran the pump inline and fabricated a bracket on the passenger frame rail for pump. Also, relocated the after pump filter to the engine bay so it will be easier to change out.

Initial thoughts: Man, the 360 is a ripper now. How much of that is a result of the reman'd engine I don't know, but I have gone from a 2 barrel on the iron intake to the 4 barrel sniper on the aluminium intake and it feels like a whole new ride. Shop set up the Sniper at 700 idle and I am reading between 13 and 14 AFRs at idle. So a pretty standard setup. Only been driving it a couple days, but so far it seems great. Worlds different from the old setup.

Only question I have out there, is that my throttle response is great, but at the same time, I feel like it is a little "light on the trigger". Meaning it comes on quite fast, and I don't feel like I can roll into it as gingerly as I did before. This may be as simple as the linkage though as I have not gotten in there to examine. But I feel like only a slight press of the pedal gets me all the output I desire, plus some. Have not even gone near 3/4 or full throttle on this thing yet. Anyone else have any issues with the linkage and acceleration with their new setup? Seems to be set up just fine, just a very sensitive pedal now.

The shop has encouraged me to run VR1 10w-30 with napa gold or WIX filters with the new engine as well as 93 Octane (I believe this to be all good advice). I asked them about ethanol free, but they seemed to think running 93 would be better.

Curious as to how others have their Sniper set up initially as well as what gas you are running?
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derf
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Re: Sniper EFI Installed

Post by derf »

I know most Holley fuel injection systems have a procedure to make sure the TPS (Throttle Position Sensor) is calibrated correctly. You may try running through that to smooth out the throttle response.

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1979bettywhite
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Re: Sniper EFI Installed

Post by 1979bettywhite »

Thanks derf.

I did some digging and it seems the Sniper EFI calibrates this function at every key on instance. But I need to do some more reading on it. Some people also mentioned checking the linkage to make sure nothing is binding. That was going to be my first line of defense. But since I got it back yesterday, it has been pretty cold out and I haven't really wanted to freeze my butt off looking everything over.

As soon as it warms up, I will be going over everything to see what all the shop did. Although I firmly believe in their workmanship and attention to detail. Also, the head mechanic, who did all the work, told me to bring it by with any questions etc. I have. I have no doubt they will stand behind their work and help me work through any issues with it.

For what it's worth, he said he has done many, many EFI installs from different manufactures and cobbled together systems and he said he would hands down always choose this Sniper system. He said this was the simplest and best running application he has come across over the years.

KJ Ryu
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Re: Sniper EFI Installed

Post by KJ Ryu »

I had that same issue with my 401. I wound up dropping the idle to 620rpm. It still wants to take off hard but, it's more manageable.
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

Topic author
1979bettywhite
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Re: Sniper EFI Installed

Post by 1979bettywhite »

Sounds like mine as well. Thinking about dropping the idle down as well.

I checked multiple times on the way home last night and the TPS always reset to 0% on coming to a stop. So I believe the linkage is fine, although I will physically check it today. But TPS wants to go from like 2% to 10% pretty quickly (sensitive pedal). I don't think I have had it over 15% yet and it's all the pickup and power I want, lol. Wondering how much is actually out there past 15% throttle. Maybe it tapers off significantly after this?

I may just have to learn to drive it like it is.

KJ, I assume you went back through the setup wizard when you reset the idle?

Also, as a side note, what have you guys done in terms of mounting your Sniper screen? I think I am going to fab up a bracket that will mount to the bottom of my dash and angle the screen up towards me. Then tuck all the excess wire back behind the dash.
Last edited by 1979bettywhite on Thu Mar 07, 2019 6:45 am, edited 1 time in total.

will e
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Re: Sniper EFI Installed

Post by will e »

How do you think the quick throttle will be on the trail? Sometimes you want to be able to finesse the jeep over things.
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derf
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Re: Sniper EFI Installed

Post by derf »

One other thing to tune on Holley FI is the idle air control (IAC) setting under throttle. It could be that it's opening a lot when you are on the throttle. I know my system goes to 30% open when I'm on the throttle. Mine seems to do reasonably well on the road with that setting. Though if I was dealing with a touchy throttle, I'd check to see what it was set to and maybe dial it back. If I had that issue on mine, I would first drop it maybe to 20 or even 15% and keep dialing it in from there.

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1979bettywhite
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Re: Sniper EFI Installed

Post by 1979bettywhite »

Cool, thanks, I will take a look here in a few minutes.
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babywag
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Re: Sniper EFI Installed

Post by babywag »

Holley is now selling progressive linkage kits for this very reason.
It hits all 4 immediately instead of primaries then secondaries ~40%. Piss poor design for most vehicles.
-Tony
'88 GW (aka Babywag)

rocklaurence
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Re: Sniper EFI Installed

Post by rocklaurence »

Another test you need to do: Afer the engine is at operating temp, At a stop, apply the brakes, give full throttle and slowly let off the brake peddle until the rear tires start SMOKING!! [-:

Topic author
1979bettywhite
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Re: Sniper EFI Installed

Post by 1979bettywhite »

babywag - so the linkage kits moves it to the latter of your comment? Primaries then secondaries. What I am experiencing and I am sure most others are the same is as you mention in your former comment about all 4 lighting up immediately. It would seem better (and more efficient) to run things as you said, primary then secondary at 40%. Do you have a link to the linkage? (pun intended)

Rock - I have no doubt if I were to hit it with some force now, even without brakes it would bark the 33" bfg muds, lol. But as the engine is fresh off a reman, I am taking it easy for the first 500-1000 miles.

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1979bettywhite
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Re: Sniper EFI Installed

Post by 1979bettywhite »

Nevermind, found it here:

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

This has to improve overall efficiency as well I would guess. Got one on order.

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1979bettywhite
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Re: Sniper EFI Installed

Post by 1979bettywhite »

This is a good depiction of what is happening and what changes with the installation of the progressive linkage:

https://www.youtube.com/watch?v=YFDibprdfW4

Although I don't know if I would advocate the manual bending of the new linkage. Maybe just go the adjustable route. Obviously more expensive though.

I will report back next week when I get the linkage installed and set up.
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melford72
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Re: Sniper EFI Installed

Post by melford72 »

I will report back next week when I get the linkage installed and set up.
Let us know how the install goes and how the progressive linkage affects mileage. Excited to hear.
70 Custom Special
Not running at the moment, but LMG/4L60e in the works! :mrgreen:

Previously, 72 Wagoneer
Carbed, Cammed, and Lifted

Topic author
1979bettywhite
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Re: Sniper EFI Installed

Post by 1979bettywhite »

melford72 wrote:
I will report back next week when I get the linkage installed and set up.
Let us know how the install goes and how the progressive linkage affects mileage. Excited to hear.
Installed yesterday. Literally took 5 minutes.

Initial impressions is almost night and day. And I thought the Sniper itself was night and day! Much more "streetable" in my opinon. I have my old pedal feel back as well. It is still fairly sensitive on the input of throttle, but you ease into the power band. Before I only had to apply like 5-7% and I was taking off the line harshly. This is much improved and I can input 10-20% throttle and not rocket off the line like before. Makes the ride much more enjoyable.

And this is from a little $14 part. If you have an older holley carb, you may be able to just rob the progressive linkage off there as well.

In setting up my TPS number, I found that the secondaries were opening at about 48-49% throttle. A little more than claimed by EFI Pros at 40%. If you want this number to be lower, you can opt for the adjustable progressive linkage, or maybe even bend this one a little.

So if you are wanting more easy throttle modulation, especially for off road situations, I would highly recommend this fix. Also, if you just want some better street driving, and a less sore calf muscle, I would go this route as well.

Nice thing is, if you ever want to impress someone with your old 360, just swap back in the fixed linkage and rocket off the line.

I will report back on fuel mileage. But I believe this should help things out.

Mikel
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Re: Sniper EFI Installed

Post by Mikel »

Very cool. Anxiously waiting for MPG figures :mrgreen:
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az chip
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Re: Sniper EFI Installed

Post by az chip »

I think you are supposed to update the software when you install the progressive linkage.

See link

https://forums.holley.com/showthread.ph ... ve+linkage
'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.

KJ Ryu
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Re: Sniper EFI Installed

Post by KJ Ryu »

:idea: Hmmm, now I gotta go through my pile of old carbs. I probably already have the parts to convert mine.
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

Topic author
1979bettywhite
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Re: Sniper EFI Installed

Post by 1979bettywhite »

az chip wrote:I think you are supposed to update the software when you install the progressive linkage.

See link

https://forums.holley.com/showthread.ph ... ve+linkage
That is correct, although you might already be fine. Mine came with 1.1.25 installed. I think you need 1.1.7 or better. If you do need to update, there are numerous postings/videos/walkthroughs etc. out there for updating.

Driving it to work for the second day in a row today, and I am enjoying this linkage more and more. Really helps on the streetability as I said. Had a little traffic to deal with this morning, which was not a problem with this linkage. But would have been more aggravating with the fixed linkage.

I am sure MPG won't improve greatly, but it should improve some for sure.

Topic author
1979bettywhite
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Re: Sniper EFI Installed

Post by 1979bettywhite »

As an update to this, I have been running a couple weeks with the progressive linkage. Still think it makes driveability so much better in terms of pedal feel, throttle response and smooth acceleration. I don't know that I am seeing a change in the MPGs, getting about the same with either linkage. But I still think it is worth swapping to the progressive linkage for those that may be debating it.

I am wondering if I need to dig deeper into the tuning of my Sniper. Currently I am set at about 13.5 AFR for idle and 14.1 cruising. Idle speed set at 700. I notice that my IAC usually sits around the 10-12 mark and opens up to 20 when I start accelerating. Drops close to 0 on decel, and then comes back in to stabilize once you get back to an idle. I think this is a pretty standard setup. I know if I leaned it up a bit I might pull some extra fuel economy out of it, but I don't know if I want to run the risk of it being too lean. Has anyone tinkered with the sniper for better fuel economy?
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