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Sniper EFI Initial Startup and Troubleshooting


Let’s be honest, some of us really struggle
with technology and switching from a carburetor to a Sniper EFI system, well, that can be
a little bit overwhelming, but it doesn’t have to be, let me take some time and show
you how to troubleshoot and better understand some of the basic start-up needs when installing
a Sniper EFI system from Holley. Let’s start with our switched twelve-volt
power source. In this case, in the Sniper it’s a pink wire. This needs to have power when the key is in
the run position and no power when it is in the off position. There is a caveat though, it also requires
power when the key is in the cranking position and you are cranking the engine. To check this, all we need is either a 12-volt
test light or a multi-meter. Both of which you can find at your local auto
parts store for less than $20. First, you will need to connect the ground
lead to a good grounded source. Now touch the pointed tip of the test light
or your multi-meter to the wire or terminal that you are thinking about using. In cases where you can not get to the bare
wire or make contact with the terminal, you may have to probe the wire insulation, it’s
not the best scenario, but it does work. Just remember to use some electrical tape
to cover the puncture of the insulation afterward, that way you can prevent any accidental contact. Now as you are holding the test light to the
wire or terminal, turn the key to the run position. If the source that you chose is a switched
source, the test light should now light up or if you are using the voltmeter, you should
see somewhere around twelve volts or battery voltage. We also need to check that we have twelve
volts in the cranking position. With the test light or multimeter probe still
on our wire, turn or have someone turn the key and crank the engine for just a couple
of seconds. The test light should stay lit when you go
from the run to the cranking position. If you are using the voltmeter, you’ll see
a voltage reading but remember with the extra load of the starter and the battery, the voltage
is going to drop below twelve volts while cranking. If you don’t have power in the run or cranking
position, you’ll have to choose another wire and re-test. Most vehicles are equipped with a keyed ignition
switch that can supply both voltage in the run as well as the crank position. You can tap into it right at the ignition
switch itself, somewhere in the steering collum, or under the dash, or like we did right here
at the fuse panel. Some ignition switches do not provide twelve
volts in the cranking position, the easiest way to correct this is to replace the switch
entirely with one that does. Once you have verified that you have twelve
volts of power in the run, as well as in the cranking position, go ahead and finish the
Sniper EFI installation and complete the wizard. Once the calibration is installed, go ahead
and turn the key off but before we start the engine we need to take a look at a few other
things first. The first thing that you’ll notice when you
turn the key on, is a tech screen, similar to this one. This is the normal initialization screen and
will appear anytime the unit is powered up. As the Sniper boots up, this screen will disappear
after a few seconds and the home screen will then be visible. After powering the Sniper up, you should also
hear the fuel pump run for approximately five seconds. This is assuming that you used the fuel pump
relay circuit that is incorporated in the Sniper EFI harness to power your pump or to
trigger a larger relay if needed. You should also hear the injectors pulse once,
priming the engine with a shot of fuel. This can be kind of hard to hear, especially
if your fuel pump is loud. If you remove the air cleaner and have a buddy
listen in the engine bay, you can verify that the fuel primed, which happens about two and
a half seconds after you turn the ignition switch on. You’ll notice that there is no choke on the
throttle body like your typical carburetor has. There is no need to pump the accelerator to
activate the choke mechanism either. In fact, you shouldn’t even have to touch
the accelerator pedal at all if you follow the idle setup instructions correctly. If you press the accelerator pedal and you
passed 60% on the TPS, it goes into what is called a clear flood safety mode. This prevents the injectors from firing and
flooding your engine. To reset it, you’ll need to turn the ignition
switch to the opposition for at least five seconds and then restart. Pay close attention to the initialization
screen as you start the engine. When starting the vehicle while the handheld
is still initializing will look something like this. You’ll notice the screen goes blank for a
second or two before it reboots. This is normal. For the best starting performance, you should
wait at least three seconds, allowing time for the fuel prime to happen, which will help
with starting. Waiting five to six seconds before starting
the vehicle allows the handheld to boot up completely and now when you crank the engine,
the handheld screen shouldn’t flicker or go black. If you notice the screen flickers or goes
blank at any time during the startup process, here are a few possible causes. The most common cause is low battery voltage. Use the monitoring capability of your handheld
to check your battery voltage. If your battery reads less than twelve volts
without a load, the battery may be just weak or possibly have a bad cell. If the battery is low, use a smart charger
to charge your battery. To avoid possible damage to sensitive electronics,
we recommend only using the smart charger. If you do not have a smart charger, it’s best
to eliminate the Sniper EFI unit from the system by disconnecting both the positive
and negative battery leads at the battery while you are charging it. To check your battery under a load, crank
the engine and watch the reading on your multimeter. You should see around twelve volts initially
and the reading will drop as the load from the starter is applied. We don’t like to see the reading drop below
eleven volts under a load and the lower the reading, the more likely you are going to
have hard starting issues. A bad can bus connection could also be to
blame, recheck the connection by removing and reconnecting the handheld so that the
main wiring harness can bus connector. If you have added a can bus extension cable
to your set up, be sure to check those connectors as well. Well, I hope these tips helped you troubleshoot
any potential problems that you may have with your Sniper EFI install. Nine times out of ten though, it comes down
to either faulty wiring, bad electrical connections, or not following the directions correctly. Take the time and do it right the first time,
you’ll thank me later. For more information on troubleshooting your
Sniper EFI system, or to see any of our other great automotive products, visit our website
at Holley.com

2 thoughts on “Sniper EFI Initial Startup and Troubleshooting

  1. The problem I had with my setup was the the idle was super high…like 1200 rpm. I thought I had a vacuum leak or something equally complicated (maybe I need a spacer below the throttle body, how's my timing) but it turned out that the idle speed screw was cranked in too far. The instructions never even mentioned the idle screw and I only figured it out by consulting some random guy on YouTube's home video. It would be a really good idea for you guys to beef up that section of the instructions. I really expected that issue to be covered in this video as well.

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