Holley Sniper EMI/RFI

[NorCalBronco]

Been having trouble with my new blueprint motor with sniper efi where the ecu does a "reset" and the computer basically restarts, especially, but not only on higher throttle situations. The holley forum guys all seem to believe this is an EMI/RFI problem. If you look at data logs you from the sniper everything gets wacky and reasdings revert to negative times etc. I did a test running the motor without an aircleaner and had the spark plug wires and distributor wrapped in aluminum foil and it seemed to run fine for the entire test. As a result I bought some MSD super conductor spark plug wires, spark plug wire looms that runs the wires to the front of the valve covers before going up to the distributor, and a smaller diameter aircleaner that doesn't touch the wires at all. I got the new stuff all installed last night and took a test drive today. I was able to go for a couple mile drive with almost no problems, but had what looked like a quick reset twice in that drive. I got home and let it idle a bit and started having more and more resets to the point where it would barely run. It appears I sadly have more work to do.

What other things have people done here specifically with their Broncos to address this seemingly common problem with these units? Next for me is a plastic air cleaner stud and to start playing with some ferrite beads. Some people have recommended a different distributor cap. There is a Holley "hall effect" distributor that is plug and play with sniper units. Hopefully can avoid that as its $$$

This is so maddening because Im so close to being able to just take my Bronco for a drive for the first time in basically a decade

 

[raleigh_bronco]

I just installed a brand new BP306, but haven’t cranked it yet..
Did your engine arrive with a metal shield installed between the dizzy and Sniper? I assume this shield is intended to help with EMI? I also purchased the Duraspark dizzy for timing control.

 

[NorCalBronco]

I just installed a brand new BP306, but haven’t cranked it yet..
Did your engine arrive with a metal shield installed between the dizzy and Sniper? I assume this shield is intended to help with EMI? I also purchased the Duraspark dizzy for timing control.

Nope, no shield. Are they installing one now? Kind of like this thing? Rf Shield. Do you have a picture?

 

[reamer]

Go Edelbrock Pro-Flow 4, Running 2 seasons now, Not 1 Issue, Stored all winter. Rolled the window down, stood outside, reached in, turned the key, Fired right up!
All you got there is an electronically controlled Carburetor, not fuel injection..... Didn't work in the 80"s still issues today....

 

[BGBronco]

You need to get a shield. Mine is made out of aluminum foil and electrical tape. If you find one for purchase, please let me know.

 

[rocknhorse76]

Find a local sheetmetal fabrication shop and have them make a shield for you.

 

[rocknhorse76]

Go Edelbrock Pro-Flow 4, Running 2 seasons now, Not 1 Issue, Stored all winter. Rolled the window down, stood outside, reached in, turned the key, Fired right up!
All you got there is an electronically controlled Carburetor, not fuel injection..... Didn't work in the 80"s still issues today....

The main issue is that the ECU is mounted to the front of the throttle body right behind the distributor cap and plug wires. They don’t work well with high voltage in close proximity to them. A simple sheetmetal shield should fix the issue.

 

[toddz69]

All you got there is an electronically controlled Carburetor, not fuel injection..... Didn't work in the 80"s still issues today....

I think the millions and millions of GM vehicles (and other makes) with TBI systems in the late 80s/early 90s would beg to differ. There are still many of those vehicles on the road today, 30-35 years later still running reliably. Sniper IS fuel injection - it has fuel injectors and an ECU. It doesn't have float bowls, jets, metering rods or carb parts. There were electronically controlled carburetors in the '80s, including on Broncos, and you're right, they were awful.

The drawback of Sniper (and all the Holley products that pre-dated it) along with FiTech, MSD, and all the other aftermarket injection kits is that their universal nature means they are not optimized for any one vehicle/installation, probably suffer from varying degrees of quality on the installation, and lack the development dollars/expertise/time that the OEMs can spend on their systems.

Todd Z.

 

[reamer]

Anything that pours fuel into a common intake to feed cylinders, no matter how controlled, is a carbureted system .... Pro flow is actually port injected with 8 individual injectors and a remote "brain box" not susceptible to the heat and EMF......

 

[toddz69]

Anything that pours fuel into a common intake to feed cylinders, no matter how controlled, is a carbureted system .

No, it's still fuel-injected, it's just a 'wet' system like a carburetor with fuel atomized into the air traveling through the manifold. As you know, your Pro-Flow (and my Ford SEFI) are 'dry' systems with no fuel in the intakes (up to the port locations). And since port injection (and now direct injection) are superior systems, throttle body systems are no longer used.

To the OP - I wish you luck with solving your issues. I had the first gen Holley fuel injection system on my Bronco for a bit in the mid-90s. I had some EMI issues with it that I was not able to resolve then either. I went back to a carb and then swapped in my Mustang SEFI engine in '97 and never looked back.

Todd Z.

 

[nvrstuk]

100% agree with what TZ is explaining. A TBI is not an electric carb and one size fits all TBI works for some and not all.

Get on some Chevy forums and see if they have the same RF issues with the same model Sniper. Probably not because the dizzy is in the rear like Tim mentioned and the frt mounted ECU in the Sniper is "just far enough away" & partially blocked to not have RF issues.

Higher rpms = more issues you mentioned.

It's not that the spark is greater but it's because at 1,000 rpm you have 6X less sparks happening than you do at 6K rpm! Make sense? Just so MUCH more RF dancing all around that ECU and distributor.

Simple shield but try wrapping just the Sniper unit first and get your plug wires as far away from the Sniper as you can as insurance.

 

[EPB72]

100% agree with what TZ is explaining. A TBI is not an electric carb and one size fits all TBI works for some and not all.

Get on some Chevy forums and see if they have the same RF issues with the same model Sniper. Probably not because the dizzy is in the rear like Tim mentioned and the frt mounted ECU in the Sniper is "just far enough away" & partially blocked to not have RF issues.

Higher rpms = more issues you mentioned.

It's not that the spark is greater but it's because at 1,000 rpm you have 6X less sparks happening than you do at 6K rpm! Make sense? Just so MUCH more RF dancing all around that ECU and distributor.

Simple shield but try wrapping just the Sniper unit first and get your plug wires as far away from the Sniper as you can as insurance.

So maybe mount the sniper unit backwards with appropriate throttle linkage and other mods , maybe a cure?? ,,but Holley should step up and figure this out after 20+ years LOL...,, and yes a retired co worker installed a sniper on his 69 Camero a couple years ago with none of these issues..

 

[Firemanjay]

I been having the same issues. I changed spark plug wires, relocated my coil and changed, have a Rfi plate I purchased and still had troubles a low RPM. I spoke with Holley about 20 times and then someone suggested grounding the module to a head then continue to the next head and then to the frame. This has resolved about 97% of my issues. Good luck

 

[bronkenn]

That Holley distributor works well but the cap does not block the RF. You can get the MSD cap to replace it and it will block the RF. I had the same problem with mine and tried everything. Replaced the Holley cap with the MSD cap and it has been running great now for 3 years. By the way I have a FiTech but the issue was the same.

 

[nvrstuk]

Good stuff to know! I'm helping two guys with Snipers and we will try that cap.

For once MSD doesn't stand for My Spark Disappeared! lol

Thanks for posting!

 

[ntsqd]

Do not ask Captain Air Time what he thinks of MSD......... And if you do, I TOLD you so!

Anything that pours fuel into a common intake to feed cylinders, no matter how controlled, is a carbureted system .... Pro flow is actually port injected with 8 individual injectors and a remote "brain box" not susceptible to the heat and EMF......

Um, no. Do we need to deep dive into how a carb, even an electronically controlled carb works, or will you go look up Bernoulli's Principle on your own?

 

[nvrstuk]

CAT and I tested the G forces that MSD would take at a couple Sand Lake/SOB adventures!

 

[nvrstuk]

That Holley distributor works well but the cap does not block the RF. You can get the MSD cap to replace it and it will block the RF. I had the same problem with mine and tried everything. Replaced the Holley cap with the MSD cap and it has been running great now for 3 years. By the way I have a FiTech but the issue was the same.

Makes perfect sense that Holly makes the sniper and they make a distributor but they won't put a cap on it to limit the RF issues that are causing so many problems on so many Sniper installs.
Insert sarcasm emoji here " ... "

 

[NorCalBronco]

You need to get a shield. Mine is made out of aluminum foil and electrical tape. If you find one for purchase, please let me know.

There is one for purchase here: https://www.redline-motorsports.com/products/rf-shield
I don't know if its any good.

 

[NorCalBronco]

That Holley distributor works well but the cap does not block the RF. You can get the MSD cap to replace it and it will block the RF. I had the same problem with mine and tried everything. Replaced the Holley cap with the MSD cap and it has been running great now for 3 years. By the way I have a FiTech but the issue was the same.

Do you have a link to the cap you purchased?