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