Sniper EFI
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.
The whole kit is expensive but I think worth it.
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
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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
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.
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.
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?
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.
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,,
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