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How To Setup a Dual Sync Distributor for Holley Sniper EFI

Congratulations on your purchase of a Sniper
EFI system. The Sniper EFI system is compatible with several
popular ignition configurations. In this video I am going to show you how to
properly wire and set up the system for a Holley dual sync distributor using the ECU
to control timing All timing advance or retard functions will
be performed by the ECU. This ignition option starts with a Holley
dual sync distributor. Dual sync adapter part number 558-493 , a
Sniper coil driver module or a CD Box, and a compatible coil. The ECU needs to receive a clean input signal,
vehicles that have excessive Electro-magnetic interference ( EMI ) or RF noise issues can
compromise these signals, as well as other control circuits resulting in poor performance
or drivability issues. Proper grounds, spark plugs, ignition wires
and wire routing are critical for trouble free operation. Non resistor spark plugs and solid core wires
may have worked with your carburetor but they will not work with EFI. A common sign trouble is if your radio whines
with the engine running. If you have EMI or RF issues they need be
corrected. Before we dive into the mechanical side of
the installation we need to program the ecu for the proper ignition type. From the set up wizard, ignition setup icon
or the PC software select Holley dual sync as your ignition type. If you are manually setting it up, the reference
angle should be set to 50. The inductive delay set to 100 and the dwell
set to 2ms now that that’s complete lets dive into the mechanical part of the installation. Before you get started you will need to disconnect
the negative battery terminal. And remove your fuel pump relay Next You will need to properly install and
phase the distributor pick up. If your removing an old distributor remove
the ignition wires and use some compressed air to clean the area around the distributor
mounting location before pulling the distributor. You don’t want any debris falling into the
opening when you remove the distributor Remove the spark plug from the number one
cylinder and turn your crankshaft in the direction of rotation until you are approaching number
one on its compression stroke. You can stick your finger in the hole as you
rotate the crank until you feel pressure to confirm you’re on the compression stroke
or you can use a top dead center whistle. I like the whistle, because not only will
it identify the compression stroke it will also give you a pretty quick way to validate
that your TDC pointer and balancer mark are in check. Over the years I have seen many mismatched
balancers and pointers or old balancers that have allowed the outer shell to slip giving
you a false reference point. Once you have confirmed you are approaching
number one on the compression stock turn the crank to 50 degrees before top dead center
If your balancer is not indexed you can measure the diameter then multiply it by 3.14 divide
that total by 360 and multiply that total by 50. Or skip the math and simply follow this chart
for common balancer diameters and measure this distance from your zero mark to find
your 50 degree reference point. Marking the reference distance on a piece
of masking tape is handy for this. Next you will need to install your distributor. Make sure that the gear is compatible with
your camshaft and dry fit it without the gasket installed. If it bottoms out without making contact to
its mating surface, you will need to remedy the situation. This is common if the block, heads or intake
have been machined. The tall deck Chevrolet 565-104 dual sync
has a slip collar so you can adjust it, or most of the time a second gasket will be enough
to take care of the situation. If your cam and distributor have been previously
run together and you are going to be starting the engine right away, a generous coating
of engine oil on the gear should be fine. If not coat the gear with a quality moly lubricant. point the rotor in the general direction you
want to position the #1 plug wire and install the distributor. If the oil pump drive does not line up, you
can turn it with a long screw driver or an oil pump priming tool. If you do not like the location or you find
that something on the distributor interferes with something on the intake you can pull
the distributor and reposition it as required just remember to keep the rotor pointed n
the general direction you want number one. now line up the rotor pointer with the black
crank position sensor. Gently snug the hold down allowing you to
still rotate the distributor. Connect the 558-493 to the distributor and
the two wire green and purple connector in the main harness the wires will be marked
Crank input Positive and Crank input negative and wire the loose red wire to the ignition
run circuit of your ignition switch. Reconnect your negative battery cable and
turn the ignition to run but do not crank. Both LEDs should be lit in the distributor. The LED closest to your crank sensor indicates
crank position Slowly turn the distributor in the direction
of rotor rotation until the light turns off then turn it back the opposite direction until
it just turns back on and lock down the distributor. Now you can reinstall your ignition wires. Now would be a great time to pick up a new
set and some fresh spark plugs at the same time. Next locate the white point output wire in
the input / output harness and securely connect it to the point input wire of the Sniper coil
driver or CD box. This is usually a white wire as well but always
check the CD box manufacturers instruction for proper wiring. Always use proper connection practices with
quality terminals and crimping tools. It’s also a good idea to seal these connections
with adhesive lined shrink tube. Never connect the yellow wire or any other
wires from the EFI system to the coil wires on a CD system or severe ECU damage will result. crank the engine over and verify that you
are showing an RPM signal on the handheld or the data monitor screen in the software. Next Select the tuning icon then the system
icon on your hand held and select static timing check. Move the slider to a base value, I generally
recommend 15 degrees and select set. using a timing light confirm that
your cranking timing is at your static timing of 15-degrees. It is important to note that you will need
to reset the static timing if you cycle the ignition off then back on, as this automatically
shuts it off. If it’s not correct, rotate the distributor
slightly until it matches Once it’s correct reinstall the fuel pump
relay and start the engine. Once again set the static timing set to 15
degrees and confirm that your timing is still at 15 degrees. If you’re thinking this is a redundant timing
check you are correct, I would rather check my timing twice then hurt my engine once. You can then select close on the static timing screen
and it will allow the ECU to resume control. It is normal to see the timing fluctuate at
this point. This is caused by the idle timing control using
the timing to help stabilize your idle speed. You can know set your desired timing through
the hand held or the pc software. For more helpful Sniper EFI tech tips and videos go to

12 thoughts on “How To Setup a Dual Sync Distributor for Holley Sniper EFI

  1. Holly crap batman 😕, I wanted this distributor with my Holley sniper but this makes me want to keep it a little more simpler.

  2. Wouldn't you want your timing to go up as rpm goes up wanting to get this but doesn't make sense to me u set static timing at 15 at idle and when you rev it up you want it to be at 15 so wouldn't that be the same as locking a regular distributer at 15

  3. I know this is an old video, but it appears you have no oil pump installed in the eng? For the guy's that don't know; if you move the rotor to the location you want the #1 tower to be, and your distributer does not seat, you will have to sync your oil pump to your distributer pump drive pin. Also you never told/showed your viewers how to confirm the static timing.

  4. why are you going 50 degrees before T D C all other sniper distributor videos say O degrees from T D C ??? and what are the 3 o rings for that come with it ??

  5. I just ordered a Holley Sniper 2300 2 barrel efi system for my 1982 Ford F150 inline 6, 4.9 Liter motor. Do I also have to get this? Thx

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