I think I have enough funds saved up to order my Holley sniper EFI kit.
Anyone have any negative experience with this EFI to share. I am going to put it on my 351w, in my '53.

I have done a lot of reading and with some install induced problems, I don't see any horrible experiences.

 

Member Sickler1 is running a Sniper EFI with Hyperspark ignition. He was just wiring it up around the first of May. You might give him a shout to see how it's going for him.

 

Indeed I am running this setup. Wiring is plug and play nothing crazy.you punch in some basic info on your engine setup and it's pretty much good to go.it started right up the first time.just having alittle fuel problem,need to adjust some fuel pressure and should be good. I ran into some problems because of my setup(twin turbo sbc) .iam a few months from a road test but love the sniper efi,easy to use and install.i did buy the whole hyperspark kit,this allows you to control the timing from the sniper .

The whole kit is expensive but I think worth it.

 

Also have a video of first start up on my build thread with the sniper efi.

 

I put one on my 302 about a year ago and am very happy with it. In our harsh winters here in San Diego it starts right up and runs nice. I would do it again. Now I am saving my nickels to do the Hyperspark to let it control timing.

 

Where are the pic, I’m using the stock 5.0 SD and trying to get it to run on pimpx ECU learning curve is hard for me so far but
Just getting started. I was going to try a Mustang mas air but though this would be less electric, I can’t answer that yet

 

Pic of the Mustang

 

The explorer manifold

 

I run the Sniper on my Chevy 383 with the Hyperspark Coil, CD box and distributor on my Camaro. The hall effect distributor is definitely the way to go if you can. I had a bunch of problems getting it to work right with my MSD CD box and distributor but not everyone does. The key to it is get it set up at the baseline and then drive it....let it LEARN!! don't mess with it for a few hundred miles unless something is really out of wack. You may get some bogging or hesitation or some lean or rich moments but it needs to learn those away....Unless you really have a race engine don't use the #3 cam setting, stick with the #2 or #1, be more conservative rather than less at least to start off.

Make sure you have a good Fuel pump set up. There is a fuel pressure regulator in the Sniper itself but if you can mount a fuel pressure gauge in the cab. Having one under the hood is helpful but only to tell you that your baseline fuel pressure is good since you can't see it when it is running.

When there are issues, the most common culprit it EMI and/or bad grounding. Follow the instructions exactly on wiring (directly to the battery and nowhere else) and be sure all your engine and frame grounds are really solid) Run the wiring away from the distributor, coil and spark plug wires to the extent you can. Make sure your spark plug wires are in perfect shape, any loose voltage may give you EMI issues. There are a few really good videos on You Tube on proper wiring of the Holley EFI system.

I am super happy with mine even though I have had a few glitches. You just can't beat having it start right up no matter what the temperature outside and idle down as it warms up. Very consistent and lots of data available on your performance. Learn how to data log as soon as you can, it is super helpful. Holley tech support is awesome if you send them your data logs. They have been really helpful to me. Everything has a bit of a learning curve so just keep that in mind. I would never go back to a carb on a new engine. In fact I have been researching whether I can get a manifold for my 223 that I can mount a 2 Barrel sniper on.

Go for it! You won't regret it

 

Thx everyone for the replies. I will have my funds saved up next month to place my order. I am going get the kit with the in tank fuel pump and just modify my new fuel tank.

I have a HEI ignition currently but cant get the carburetor right to get it to stay running. Hope to spend the time to get her running after the sniper is installed.

I am sure I will have questions, going forward, but thx the initial info.

 

Comes with pretty straight forward directions.i ran most of my wires thru the firewall and tucked it under the dash.if you go this route plan out wire route before you plug them in.good luck with it.ill be happy to help if you run into any problems.

 

Gentleman, I am about to start my wiring for the Sniper EFI...had a question as was confused in the HEI non-timing drawing...

The 7 pin connector wants a 12V switched ignition on the Pink wire (my thinking it is the control for the fuel pump replay on this harness). The manual also says to NOT use a dirty connection like a coil input.
My question, unless I go though a relay for this 12v on the pink wire, is it not the same source? Can I connect it to the key switch? Which is the same connection to the "Battery" pin on the HEI coil?

 

You can use the switched connection off the key or even better, a switched connection off the fuse box if you have upgraded that. They just don't want something that is going to create any signal noise which the coil will certainly do.

I know I am repeating some of this but it can't be emphasized enough to ensure you get a good result.

Other wiring tips:

ONLY connect the main power and ground connections directly to the battery. If you look on the sniper forums failure to do this and connecting to other power sources is often the cause of difficult to diagnose issues.

The sniper tends to be very sensitive to electronic noise. Make sure your wiring is as far from the coil, spark plug wires and other wiring as possible. Run wires perpendicularly, not in parallel wherever possible and if you want to have an extra level of assurançe use some EMF shielding. I would do that last only if you think you are having noise issued. I am not using it, but others have had to.

The sniper is also very sensitive to good grounding. Make sure your ground connections are clean and solid. Make sure you are grounded:

Battery to Frame
Battery to block
Frame to block
Block to Chassis
Chassis to Frame

I know that seems like Overkill but again when you look online for hard to diagnose issues it often comes back to grounding issues or electronic noise interference.

Just for reference I am running mine on a Chevy 350/383 with the Sniper CD box, Sniper coil and Sniper hall effect distributor with timing control. I know your set up does not use all of that. I had an MSD box with an MSD Billet distributor and for me they did not play well together. Others have had a difference experience.

Fuel Management tips:

I am using a Robmcc surge tank to feed the sniper. It uses the stock fuel pump to feed the surge tank and the surge tank has the Electric fuel pump in it.

I found my stock mechanical fuel pump could not feed the surge tank fast enough and I was getting lean spikes. I had to switch the fuel pump out to a high volume Edelbrock pump.

Make sure your return line is sized properly. If it is not adequate that may also cause some fuel management issues. I have a 3/8" back to the surge tank and a 1/4" return line back to the tank which is considered marginal from the surge tank. It has not been an issue for me but others occasionally have had some. If you already have a 1/4" line back to the tank put a fuel pressure gauge on the return and be sure it is under 5psi. 0 psi is perfectly fine.

 

Thank you much or the information:

I did some more reading last night, and yes, I am putting in a Kwik wiring harness so will have several circuits to connect to, just not there yet. I was wanting to get my engine to fire up so I might just be getting ahead of myself and need to get the wiring started. My harness has a fuel pump circuit which I need to verify has 12v in both on and cranking key switch positions and is not needed being I am using the fuel pump relay on the sniper harness. I will take note of the noise when running my wiring.

I am using their in-tank fuel pump, which seems pretty straight forward so hoping to have not issues there.

Thx again, as I am sure there will be many more questions to come,,

 

The guys on the team Chevelle forum are the most knowledgeable on the internet that I have found on the Sniper.

https://www.chevelles.com/forums/forumdisplay.php?f=89]Team Chevelle EFI Forum

EFI Prosystem has by far the best articles and information on install, set up and troubleshooting. if you email the owner he always responds. Ideally I'd you need any new items and buy from him he gives unlimited direct customer service. Really take some time digging around on the website and articles and you will find tons of useful information.

EFI Pro System