Engine Holley Sniper on an 258

[cglax6]

Nice! I went the same route. I got a relay kit from Painless and I'm very happy with it. I have a Painless harness and I was impressed with the quality of their stuff from the get-go. Remember, those fan wires on the sniper are triggers...not meant to power the actual fans.

 

[Manic Mechanic]

i have an aluminum radiator with electric fan set up on a relay to trigger on at 195 and off at 180

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[Chuck Bnvds]

It seems like you are happy with this upgrade.

 

[Manic Mechanic]

It seems like you are happy with this upgrade.

i had one let down in 3 years when the sender went bad. ive since wired in a switched back up. hopefully the sniper will take care of this issue. but I need to replace my exhaust before I can install the sniper

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[cglax6]

hopefully the sniper will take care of this issue.

Unfortunately, if a sender/sensor goes bad that gives the Sniper information, you're going to have worse issues than just a fan not turning on when you want it to. If a temp sensor fails and it reads cold, it'll start dumping extra fuel thinking the engine is cold while it reads off of the temperature enrichment chart. If you have an O2 sensor failure, the ECU will think you're getting a super high AFR reading and it'll dump extra fuel into the motor thinking it's running too lean. The latter will result in the motor shutting down on you.

That's the tradeoff of going the EFI route, but if you follow the directions carefully, you shouldn't have any problems. I haven't heard of many folks' temp senders going bad, but there are a lot of O2 sensors that go bad...but those are mostly caused by improper installation.

All in all, I really like my Sniper. I've never had an issue with it.

 

[Manic Mechanic]

Unfortunately, if a sender/sensor goes bad that gives the Sniper information, you're going to have worse issues than just a fan not turning on when you want it to. If a temp sensor fails and it reads cold, it'll start dumping extra fuel thinking the engine is cold while it reads off of the temperature enrichment chart. If you have an O2 sensor failure, the ECU will think you're getting a super high AFR reading and it'll dump extra fuel into the motor thinking it's running too lean. The latter will result in the motor shutting down on you.

That's the tradeoff of going the EFI route, but if you follow the directions carefully, you shouldn't have any problems. I haven't heard of many folks' temp senders going bad, but there are a lot of O2 sensors that go bad...but those are mostly caused by improper installation.

All in all, I really like my Sniper. I've never had an issue with it.

i agree however my failed sender was made of Chinese super quality materials. i know the risk of a bad 02 sensor and what not. but i feel confident that I will install everything well and get many years of quality service out of it all the while vastly improving my fuel economy and performance on and off road

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[007]

One thing to remember though is that if you keep your dash display handy, you can shut off the Closed Loop and Fuel Learn, effectively by passing the O2 sensor in a pinch. My O2 sensor failed 2hrs from Moab a few weeks ago and I did this on the side of the road and ran it all week and all the way home this way. I've had to do this twice and this (to cglax6's point) will be my third O2 sensor since 2017. I'm stopping by Summit on the way home and getting a Bosch one (supposedly same as the Holley, but $30 cheaper). They do need installed correctly and mine have been, but I do read forums where others are complaining about O2 sensor life. Hoping to find a Denso crossover part number.

 

[Manic Mechanic]

One thing to remember though is that if you keep your dash display handy, you can shut off the Closed Loop and Fuel Learn, effectively by passing the O2 sensor in a pinch. My O2 sensor failed 2hrs from Moab a few weeks ago and I did this on the side of the road and ran it all week and all the way home this way. I've had to do this twice and this (to cglax6's point) will be my third O2 sensor since 2017. I'm stopping by Summit on the way home and getting a Bosch one (supposedly same as the Holley, but $30 cheaper). They do need installed correctly and mine have been, but I do read forums where others are complaining about O2 sensor life. Hoping to find a Denso crossover part number.

good to know about the 02 sensor. maybe even a AC Delco unit or nkg

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[JPop]

Been looking at this for my 83CJ (with 350 SBC). What do y'all use for fuel pump? The SBC has a mechanical pump - I cant imagine this would work.

 

[cglax6]

Been looking at this for my 83CJ (with 350 SBC). What do y'all use for fuel pump? The SBC has a mechanical pump - I cant imagine this would work.

For the Sniper to work properly, you need to be able to deliver at least 60psi. They sell a master kit that comes with an in-line external pump and filters, but for that system to work properly, it needs to be installed lower than and closest to the fuel tank...not really an option for CJs. You can make it work, but it's not ideal.

The other option is to use an in-tank pump. Novak sells a direct fit solution for a stock tank. I have an aftermarket poly tank, so I used Holley's Retrofit in-tank pump. I got the returnless version that has a built-in regulator, so I didn't need to run a return line. If you want to run a return line, no big deal...the instructions tell you what to do.

 

[Manic Mechanic]

started my install the other day which included new headers as i smashed my on a rock. im currently running but need to clean up a few extra wires, run the loom, and adjust the throttle (only getting 25%) as for the pump i mounted mine on the driver's side inner frame rail. not quite as low as they wanted but convenient and very little dirt even after off roading.

i need to play with the tune but im idling right around 775 rpm

stay tuned for more updates
P.S. having a lift or access to one will greatly help and speed along the project

 

[j6824]

Been looking at this for my 83CJ (with 350 SBC). What do y'all use for fuel pump? The SBC has a mechanical pump - I cant imagine this would work.

I'm using this one:

https://www.amazon.com/ACCEL-75342-Thruster-Electric-Tank/dp/B00GWC1D88

 

[Manic Mechanic]

got her all buttoned up and test drove it. runs fanatically even on steep inclines. still in the learning phase but on the highway i was doing 65-70 at about 1900 rpm. idles like a dream. starting takes a bit longer than it use to when warm (was instant) but to be able to fire up and drive off with no babysitting is wonderful.

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[007]

got her all buttoned up and test drove it. runs fanatically even on steep inclines. still in the learning phase but on the highway i was doing 65-70 at about 1900 rpm. idles like a dream. starting takes a bit longer than it use to when warm (was instant) but to be able to fire up and drive off with no babysitting is wonderful.

I can help you with the warm start. I had that issue too. It’s a quick fix in the tune file.

 

[Manic Mechanic]

I can help you with the warm start. I had that issue too. It’s a quick fix in the tune file.

really. what do I need to do

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[73CJ]

Finally getting to put the sniper in. It started up but died wouldn’t rev up

Pulled the muffler off and found about 2 cups of burnt soy beans. That mouse was dang busy. More progress reports to follow

 

[73CJ]

Ok got the beans out. It was constantly priming . And after 1-1/4 hours on the phone with Holley they decided I needed to talk to MSD they make the Hyper spark. So I have to send it in to have them check it. Oookay
The old GM HEI worked just fine so I popped it in. Bingo!
Got the twin fans hooked up with relays.
Tomorrow morning I’ll take her for a spin!
Yee Haw

 

[73CJ]

Took her for a spin in the pasture. Starts great and runs strong. Can’t wait to get the Hyperspark distributor in though. Small stuff to finish up next
Scraped the stock linkage and cut a bracket on my cnc plasma table. It’s a direct connect to the cable now.
Easy to wire up but there’s so many dang cables it’s impossible to keep the wiring neat.

 

[TSB8C]

Been looking at this for my 83CJ (with 350 SBC). What do y'all use for fuel pump? The SBC has a mechanical pump - I cant imagine this would work.

Remove the mechanical pump and put on a block-off plate. I then used an in-tank pump with my stock metal 13 gallon tank. The pump is a Walbro # GSS342-400-791 in-tank electric pump. Can do about 60 psi, 58 needed for my system. I removed the stock pickup tube and sending unit, cut the fuel pickup tube with the sock filter on it to the correct length so that the electric pump could be connected to that pickup tube using FI rated rubber hose and clamps and hang the correct length into the tank so that the filter on the bottom of the pump would sit just a 1/4 - 1/2 inch off the bottom of the tank. Drilled a small hole in the top round part for the positive wire mounted to a nylon insert with a screw through it. My system uses a return line, with was already present in the Jeep. I then have an in-line filter up under the hood before the line enters an adjustable pressure regulator. The pump and regulator both came to about $100 total.

 

[CJ]

Remove the mechanical pump and put on a block-off plate. I then used an in-tank pump with my stock metal 13 gallon tank. The pump is a Walbro # GSS342-400-791 in-tank electric pump. Can do about 60 psi, 58 needed for my system. I removed the stock pickup tube and sending unit, cut the fuel pickup tube with the sock filter on it to the correct length so that the electric pump could be connected to that pickup tube using FI rated rubber hose and clamps and hang the correct length into the tank so that the filter on the bottom of the pump would sit just a 1/4 - 1/2 inch off the bottom of the tank. Drilled a small hole in the top round part for the positive wire mounted to a nylon insert with a screw through it. My system uses a return line, with was already present in the Jeep. I then have an in-line filter up under the hood before the line enters an adjustable pressure regulator. The pump and regulator both came to about $100 total.

View attachment 76154 View attachment 76155

Some thing to add to the above post as an option. It is expensive but allows you to run FI without any tank changes and you keep your mechanical pump. It is an external pump with a reservoir.