Solving RF Interference Issues in Sniper EFI Installations

[cmyer]

Applying aluminum foil is not a fix or even a band-aid, though it can give some clues on the source of the problem. In your case, the problem is clearly coming from the area of the distributor. Have you replaced your spark plug wires with a wire with proven capability to prevent RFI (not just "claimed" to prevent RFI)? If you've done that, have you replaced your cap and rotor? And if you've done that, have you replaced your distributor? Is there is a coil under your that aluminum foil have you replaced it?

[tdford5]

I replaced wires as I installed new I HyperSpark system (box, coil & distributor). I know it's not the fix, but just wanted to make sure what the issue was. So MSD Street Fire Spark Plug Wire Sets 5552 is what I put on. So now is it coming from the wires or distributor? I attached a couple photos. Please don't mind the mess I wanted to make sure everything was going to work before looming all the wires. I'll take any help on how to stop this and make it work. Thanks.

[gregs69rs]

Can you put the old wires back on to test?

[tdford5]

I could, but they're the same wires. This is all new. I just put on coil, box and distributor, removed the HEI distributor and install HyperSpark system and new wires with same MSD wires; only difference is the color.

[thecowwatcher]

Understanding RFI/EMI is key to troubleshooting it. Plenty of articles and videos out there explaining the basics.

I do want to point out one thing almost all of us have in common with these Sniper installs. Most of us are putting EFI on vehicles that were not originally equipped with it! So of course our chassis ground is just enough for the gauges and lights to work.

I can not stress enough how important grounding is. Just going from the battery to the frame is not enough. I have grounds from my frame to the core support, to the bed of my truck, to the cab, alternator, and one to the engine. EVERYTHING ties in to the frame and my EFI, HyperSpark and fuel pumps all ground directly to the battery. If a ground is present then remove it and clean it well, apply a corrosion inhibitor and make sure it's tight.

[thecowwatcher]

I could, but they're the same wires. This is all new. I just put on coil, box and distributor, removed the HEI distributor and install HyperSpark system and new wires with same MSD wires; only difference is the color.

So MSD Street Fire Spark Plug Wire Sets 5552 and what part number for the spark plugs? Is there a good ground from the engine to the frame?

[tdford5]

I have 0 AWG grounds to chassis and to battery, to the frame, to the engine block. Should I run a ground to the distributor? I can ground whatever I need to.

[thecowwatcher]

No need to ground the distributor. Just make sure all grounding points are clean and secure.

[tdford5]

I know I have a engine to chassis ground in the front of the engine. I believe my back ground is engine to firewall, I'll double check this evening. So it's just the lack of proper grounding the cause of RFI noise?

[Danny Cabral]

No, it can also be caused by EFI wiring too close to high voltage components (spark plug wires, ignition coil, distributor, etc.)

View from 6:52 minutes onward for more information about the datalogger "Mark Data Points" feature: https://www.youtube.com/watch?v=BQdQ...ature=youtu.be (Holley EFI Proper Grounding & Wiring Practices - Devin Vanderhoof)
Additional information for others viewing this: http://forums.holley.com/showthread....2656#post32656 (Electronic Noise Interference, AM Radio Detection - Post #53)

[tdford5]

So after pulling out wires I have three 14 AWG power wires in the same loom as my Sniper & HyperSpark wiring, but why does Holley run there hot/ignition hot wires along with the points wire (white)? Also, does the location of the ignition box matter? I've also check my grounds currently 0 AWG OFC wire - engine to battery, frame to battery, engine to firewall. I'll add a engine to frame in the next couple days. Also, I'll loom the HyperSpark & Sniper wires by themselves, hopefully this will work

[Chuck L.]

I replaced wires as I installed new I HyperSpark system (box, coil & distributor). I know it's not the fix, but just wanted to make sure what the issue was. So MSD Street Fire Spark Plug Wire Sets 5552 is what I put on. So now is it coming from the wires or distributor? I attached a couple photos. Please don't mind the mess I wanted to make sure everything was going to work before looming all the wires. I'll take any help on how to stop this and make it work. Thanks.

A dumb? Can the RFI signal be carried by the stainless wrap on those hoses?
The reason I ask is, the hose lays on the plug wires, and is nearly touching the Sniper body.

[thecowwatcher]

So after pulling out wires I have three 14 AWG power wires in the same loom as my Sniper & HyperSpark wiring, but why does Holley run there hot/ignition hot wires along with the points wire (white)? Also, does the location of the ignition box matter? I've also check my grounds currently 0 AWG OFC wire - engine to battery, frame to battery, engine to firewall. I'll add a engine to frame in the next couple days. Also, I'll loom the HyperSpark & Sniper wires by themselves, hopefully this will work

The Sniper and HyperSpark power wires go straight to the battery. The ignition wire is 12V, but low amperage.
You need to study RFI/EMI and understand transducer vs transmitter and how it relates to communication wiring. I know it sounds like a lot, but luckily we're only dealing with DC circuits here. I have Ferrite RFI Suppressors on my HyperSpark and Sniper power wires at the battery. Most likely overkill, but they are there. I have loomed all wires separate as well. The engine to frame ground should help.

A dumb? Can the RFI signal be carried by the stainless wrap on those hoses?
The reason I ask is, the hose lays on the plug wires, and is nearly touching the Sniper body.

I'd say no, but I've seen some weird stuff in my days so it could always be possible. The path of least resistance applies.

[cmyer]

A dumb? Can the RFI signal be carried by the stainless wrap on those hoses?
The reason I ask is, the hose lays on the plug wires, and is nearly touching the Sniper body.

Sure it can! Any time you put metal in an electromagnetic field you're going to induct power into that metal. And then there's the potential of turning that into an antenna or guide that transmits that field elsewhere. I'd remedy that situation, even if it's not the cause of your problem.

[tdford5]

OK pulled Sniper/HyperSpark wires out of loom and ran them by themselves got a little better like 20%. Starts but still sputters. I going to loom up spark plug wires and get up and away from the engine block/braided hoses. I do have some extra ferrite snap on beads, snap on style. I may put them on the power wires going to the battery from Sniper system. And yes, again I should have plenty of grounds, these are my 0 AWG wire grounds (engine to chassis, engine to firewall, engine to battery, chassis to battery) so hopefully we can put the ground issues to rest here.