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How To Install Sniper EFI BBD for 1971-1986 Jeep CJs


Now you can give that old Jeep of yours the
drivability and performance benefits that it deserves with Sniper BBD from Holley. I’m going to take you step by step through
the complete install, using our CJ. It’s an 84′ CJ7 with the original 258 cubic
inch inline six sporting a Carter BBD carb. Holley’s Sniper BBD kit was designed for use
on 1971 through 1986 Jeep CJs with this engine combo and although you probably won’t see
these numbers from your trusty inline six, a pair of one hundred pounds per hour injectors
makes Sniper BBD more than capable of supporting up to 350 horsepower naturally aspirated. I’m also going to show you how to upgrade
your stock ignition system with a hyper spark distributor, ignition box, and coil. Well, let’s get started. Step one is safety. We’ll remove the negative battery terminal
from the battery before proceeding. Removing the wingnuts from the carburetor
stud and the mounting stud on the valve cover will allow us to remove the air cleaner lid. You’ll also need to remove the fresh air duct. Now when you remove the base, there’s going
to be a bunch of vacuum lines connected so it’s always a good idea to use some tape and
label them so that way when we reinstall we know exactly where they go. Go ahead and disconnect all of the vacuum
lines that are on the carburetor and label them as needed. Use the appropriate wrench to remove the factory
fuel line. I’ll eliminate the hardline and block it off
with a mechanical pump later. We also need to disconnect any wires or electrical
connections that are attached to the carburetor before we remove it. And then last but not least, the throttle
linkage. Now we can remove the four nuts that secure
the carburetor to the manifold. Once that is accomplished we can remove the
carburetor assembly. If any of the vacuum lines are damaged or
appear to be damaged, now is a good time to take care of them. Clean the gasket mating surface if necessary
and install a new base gasket. Some models may have a spacer like this one
if yours does, be sure to install it with a gasket on the top and bottom. Before you install the Sniper throttle body,
it’s a good idea to install the new air cleaner bail with the included hardware. This lessens the chance of losing a screw
in the engine bay or worse yet, down the intake. Once you have got the bail secured, we can
set the throttle body on the intake and install the four nuts to secure it. Tighten the nuts in a criss-cross pattern,
then torque them to 60-80 inch-pounds. While we are here, we can reinstall the throttle
lever, simply snap it into place and check for any binding interference issues before
proceeding. Carefully re-connect the vacuum lines that
we removed earlier to the carburetor. Plug off any vacuum sources that will not
be used on both the Sniper throttle body and the engine. Sniper EFI includes a coolant temp sensor. This needs to be installed in a 3/8ths-inch
port in either the intake manifold or your cylinder head. To avoid making too much of a mess, you can
drain some of the coolant from the radiator before removing the old sensor or plug. I’m going to install the sensor in the intake
for this particular vehicle. Never install the temp sensor in the thermostat
housing or any location that it will not see a constant flow of coolant. Make sure you apply some thread sealer or
thread tape if your sensor does not already have some. Be careful not to cross thread or over tighten
the sensor. Once installed, you can connect it to the
appropriate lead that comes from the throttle body. Next, you’ll need to locate a good position
for locating the wideband O2 sensor in the exhaust system. It should be located as close to the engine
as possible while still providing a good average of all the cylinders. If your Jeep has a header, the sensor needs
to be one to ten inches after the collector. Remember the O2 sensor needs to be positioned
at least ten degrees from level and at a downward angle. This helps prevent any condensation from building
up on the tip and possibly damaging your sensor. We can now install the O2 sensor, tighten,
then connect it to the lead that comes from the throttle body. Now we can move on to the electrical connections. You’ll need a clean dedicated 12-volt switch
source. This needs to have the power not only in the
cranking position but also when the key is in the run position. First, though, we’ll need to reconnect the
negative battery terminal so we can do some testing. Using a test light, I’ve located the clean,
switch 12-volt source that has power in both the run and cranking position. I’ll connect the pink wire from the Sniper
throttle body here with the appropriate electrical terminal. First, we’ll need to connect the power harness
to the corresponding connector found on the Sniper throttle body. You can temporarily lay out the power harness
but do not zip tie it just yet. In this case, to gain access to the cabin,
I’m going to go through this grommet in the firewall. I ran the pink wire inside the Jeep to the
fuse panel and now I’m pulling the cam bus cable for a handheld through to the engine
bay and I’ll make the connection to the throttle body. And then we will need to go inside and connect
to our 12-volt switch source. Now you need to be sure and disconnect the
negative battery terminal again before we proceed. Now we can terminate the ends of our red and
black wire and connect them to the corresponding terminals on our battery. Never run them through a switch, relay, or
distribution box. The heavy blue wire that you find in the wiring
harness is to power your fuel pump. Since it has a built-in relay, it can be connected
directly to the positive terminal found on your fuel pump. You have lots of options when it comes to
supplying fuel to your Sniper EFI system. For this install, I’m going to use this Sniper
replacement fuel tank and a Holley direct fit EFI pump module. Since I’ll be replacing the stock tank with
a new one from Sniper EFI, I’ll first need to remove this rock guard and remove the old
one. Next, I can install the new fuel pump module
in our Sniper tank before installing it. Start by installing the included O-ring in
the recess channel, then line up the indexing pin on the pump with the index hole found
on the Hydra-Mat. Press firmly on the filter base until it is
fully seated. Now slowly feed the filter into the tank,
making sure that you don’t cut or snag it on the tank opening. Once the filter and pump assembly are in the
tank, you’ll have to remove the two screws that hold the fuel level sender and float
arm to the module. Now feed the float into the opening and reposition
it so that the screws align with the mounting tab on the module again, then tighten both
screws. Drop the module the rest of the way into the
tank, aligning the tab on the tank with the notch in the module. Then install the new retainer ring and tighten
it with a brass drip and hammer until it is fully seated. Next, we can plug in the included harness
lead and make the connections for power to the pump using the heavy blue wire from our
Sniper harness. Make sure you use a good clean chassis ground
and since the Holley module also includes a fuel level sender, we can connect it to
the factory wiring for our dash gauges. We need to run a supply and return fuel line
to the Sniper unit in the engine bay. I’ll start at the tank, and using the correct
EFI rated fuel lines, I’ll install and secure them to the tank. Make sure you are using the EFI rated fuel
line and clamps. Install the new Sniper fuel tank, then reinstall
the factory rock guard. When supplying fuel to any EFI system, we
recommend 100-micron pre-filter and a 10-micron post filter. Since the Hydra-Mat in our Holley pump module
acts as our pre-filter, I only need to add this 10-micron filter to our supply line. Once again I’ll secure it using EFI rated
clamps. Now I can route and secure the fuel lines
along the frame rail, working my way from the tank to the engine bay. Be sure to avoid any moving parts or high
heat areas that could compromise the fuel line’s integrity. Once you have the fuel line safely secured
and run to the engine bay, we can cut and remove any excess hose then install the fittings
using EFI rated clamps. Be sure you can connect the fuel lines to
the appropriate fittings found on the Sniper throttle body and tighten. Sniper has a built in fuel pressure regulator,
so there is no need to purchase or mount an external unit. Let’s focus on the ignition system now. Sniper EFI will work just fine with the stock
mechanical distributor and induct a coil but if you want to get all the benefits of ignition
timing control, you’ll need to upgrade to a magnetic or a Hall Effect style distributor. We have several distributor options from MSD,
Holley, as well as Sniper for timing control and complete wiring instructions can be found
on our website. The first thing that we’ll need to do is rotate
our engine and find the top dead center on the number one cylinder and make sure that
it’s on the compression stroke. To locate the number one cylinder, simply
trace the plug wire from the front cylinder, back to the distributor. They are numbered 1-6 from front to back and
put a mark on both the cap and housing. Slowly rotate the engine in the direction
of normal operation until the rotor is aligned with your mark. We also need to verify top dead center on
the harmonic balancer, the timing indicator should be real close to the zero mark on your
tab. If not, continue rotating the engine until
they both align. Now remove the coil and plug wires as well
as any vacuum lines that may be attached to the distributor. Notice that the rotor is pointed tot he location
of our number one sparkplug wire. It’s a good idea to wipe or blow off any debris
around the base of the distributor that may fall into the engine once it is removed. Loosen and remove the bolt to the distributor
hold down, next gently lift up on the distributor housing to remove it. Note that the rotor rotates slightly when
it’s removed. This is due to the helical cut gears and you
will have to take this into account when re-installing a new distributor. On this Jeep, I’m going to be installing the
Hyper-Spark distributor, CD ignition box, as well as a new coil. Since they were designed to work with the
Sniper EFI kits, they will be an easy install. Install the new gasket to the base of the
Hyper-Spark distributor. If needed you can apply a small dab of silicone
to keep it in place. Be sure to coat the new gear with some engine
oil or if your engine is new or just been re-built, apply some grease to the gear instead. I like to try and position the rotor so it’s
pointed towards the number one plug wire, just like it was on our old distributor, but
the direction in which the rotor is pointed isn’t as crucial since the phasing cap will
index it correctly. It simply changes the position of the number
one plug wire on our distributor cap and may move the wire leads under the distributor
to a less than desirable location. Remember, the rotor will rotate slightly during
the installation process so you have to compensate for this. In some engines, it may even be necessary
to rotate the oil shaft slightly to get it to align with the drive on the bottom of the
distributor. You can do this using an old oil pump priming
tool or in some cases even a long flat screwdriver. Once you have the distributor fully seated
and the drive gear and oil pump are meshed, place the black adaptor ring on the distributor
and position it so the tab on the ring drops into the notch found on the distributor housing,
then install the clear cap that is included in the kit over the rotor. Slowly rotate the distributor housing until
the clear cap drops down onto the rotor and the tab found on the adaptor ring engages
into the recessed notch on your clear cap. This step phases the distributor housing,
finally reinstall and tighten the distributor hold down. With the distributor alignment process complete,
the rotor should now be pointed in the general location of our number one spark plug terminal
once we install the distributor cap. You’ll notice a small raised notch on the
side of the clear cap, this notch indicates the location of the terminal for our number
one plug wire. I like to make a mark on the distributor housing
directly below this notch in the plastic cap, verifying the location of our number one plug
wire. Install the new distributor cap, then secure
it with the included screws. We can then install the number one plug wire
on the terminal above our mark. Go ahead and install the rest of your plug
wires, following the correct firing order and distributor rotation. On Jeeps with a 258 cubic inch engine, the
firing order is 1-5-3-6-2-4 in a clockwise direction. Note that the stock plug wires will not work
on the new cap. Your plug wires will have to be switched out
for a set that works with an HEI style terminal. Once all the wires are installed, use the
supplied wire retainer to keep them in place. Next, you’ll need to locate the three pin
wire harness that’s supplied with the Hyper-Spark distributor. Plug the two pin connector from the distributor
harness into the corresponding two pin connector found on the Sniper main harness. The connectors are keyed and the green and
purple wires should match up. Now plug the three pin connector on the distributor
into the three pin connector from the harness. Next, we’ll need to connect the pink wire
to the same switch 12-volt source that we connected our pink wire from the Sniper main
harness to earlier. Installing one of our Hyper-Spark CD ignition
boxes and coils are not required to run Sniper EFI but it can definitely give your Jeep some
added benefits and they are super easy to install with our plug and play connectivity. Locate a safe and convenient location to mount
your Sniper CD ignition box that’s away from high heat and moving parts. I choose the inner fender well. It was necessary for me though, to move the
starter solenoid down about 6 inches from its original position. Connect the main wire harness to the box and
run the red and black wires directly to your battery. Our Hyper-Spark CD ignition box needs a points
output signal, we can obtain that by using the auxiliary input-output harness that’s
found in the Sniper EFI kit. Simply plug the harness into your Sniper EFI
and connect the white points output wire from the Sniper throttle body to the white wire
found on the Hyper-Spark ignition harness. Any un-used wires on the harness can be unpinned
and removed or simply tied up and out of the way for future use. Run the light gauge red wire that’s on the
connector next to the white wire to the same switch 12-volt source we used for our pink
wires from the Sniper EFI and Hyper-Spark distributor. We can now mount and install our Hyper-Spark
coil. Don’t forget to connect it to the distributor
with the coil wire. The Hyper-Spark ignition can also be used
with most stock and aftermarket coils. If your coil does not use a TFI style connector,
simply cut the connector off and use the ring terminals. Then secure them to the appropriate terminals
found on your coil. Orange is for positive and the brown with
an orange tracer is the negative. If your vehicle has a balance resister in
line with the coil wiring, we recommend that you by-pass it or remove it entirely from
the system. Since I’m not using the coil that’s in the
stock location, I’ll terminate the wires and remove the coil. We are now ready to launch the startup wizard. This can be done using the handheld touch
screen, so we will first need to reconnect our negative battery terminal that way we
have power. But before we do, it’s always a good idea
to flush the fuel lines of any debris that could cause damage to our injectors or other
fuel components. Simply remove the fuel supply line and from
the throttle body, and place it in a petroleum safe container, that way it catches any debris
that may have entered the lines. Now we can start the wizard. Turn the key to the run position but do not
crank or attempt to start the engine at this time. From the home screen, select the wizard icon
from the main menu, then select the Sniper system that you are installing. BBD in our case. Next, you’ll have to select the number of
cylinders that your engine has, then select next. Use the slider bar to input the cubic inch
displacement of the engine, 258 for our engine. Now we need to set the desired idle speed
for coolant temperatures above 160 degrees Farenheight. Use the slider to set the target RPM then
press next. The ECU also needs to know the cam type. For most street and street performance camshafts,
the stock mild selection is what you will use. Select the cam type and then click Next. This step is to select the type of ignition
system that you are using. As I talked about before, Sniper EFI will
work with stock and performance inductive coils and CD boxes for installations that
are not using timing control. If you want to control ignition timing, you’ll
need a magnetic or Hall Effect distributor. I’ve installed the Hyper-Spark distributor
and ignition system so I will select the Hyper-Spark option, click next, use the cursor to select
the total timing at wide open throttle, I’m going to set ours at 32 degrees. After you have answered all of the questions
in the wizard, a calibration will be created for you. Press the start button to send the calibration
to the ECU and wait for a screen to appear indicating the file is uploaded. Press OK. Once the file is uploaded, you’ll need to
cycle the ignition key off, then back to the run position again. You should hear the fuel pump prime for approximately
five seconds. I like to go ahead and cycle the key another
four times, pushing any fuel and debris through the fuel lines and into our catch container. Once you are satisfied that fuel lines are
clear, you can re-attach the supply line to the throttle body and tighten the fitting. One more cycle of the key should pressurize
the lines and now is a good time to thoroughly check the fuel system for any leaks. Before we can attempt to start the vehicle,
we need to verify that the system sensors are operating properly. To do this, turn the key to the run position
and from the home screen select the monitor icon, then the monitor screen. An icon named initial startup should appear. Select this icon. Engine RPM should show stall. Once you crank the engine it will show syncing
and then show the actual engine RPM. The TPS or throttle position sensor should
read zero. If you slowly depress the throttle to wide
open, it should read between 85 and 100 % at wide open throttle. If it doesn’t, you’ll need to verify that
your throttle linkage is allowing full travel of the throttle arm. Map or manifold air pressure sensor should
read from 95 to 102 but at higher elevations, it could read as low as 75. The CTS or coolant temperature sensor reads
engine temperature and it will read ambient coolant temperature until the engine is started. The IAC or idle air control position, I’ll
address this when we get to the idle setting and throttle placement settings section. Battery, it will show the normal battery voltage
and you should read at least 12-volts minimum. If any of these sensors do not read properly,
the issue must be resolved before proceeding or attempting to start the engine. If you have not done so already, now would
be a good time to go back and make sure that you have all of the wiring routed away from
moving parts and high heat areas and that the connection is secure. wrap up and ziptie any loose or excess wires. You can also define any un-used wires in the
input and output harness now. You should also perform the pre-start checklist
that is outlined in the installation manual. With the handheld still on the initial startup
screen, turn the key and crank the engine over. Watch the RPM parameter, it should go from
stall, to syncing, then to registering the actual engine RPMs as it fires and starts
running. If the engine does not fire, you’ll need to
follow the flow chart in the Sniper EFI troubleshooting guide found at Holley.com. If the engine runs but you find that idle
is too low and it wants to stall, you may have to open up the idle speed screw on the
throttle body slightly. Once the vehicle is started and is idling
good, double check for any fuel or coolant leaks. We’ll also need to verify the ignition timing
used in the touch screen and the timing light. First, we need to lock the static timing,
to do this from the home screen select the tuning icon, then select system, and then
static timing. Slide the cursor to 15 degrees and click set. Now you will have to connect the timing light
and verify that you have 15 degrees of timing at the balancer. If it does not read 15 degrees before top
dead center, you’ll have to loosen the distributor hold down and rotate the distributor until
the values match. Don’t forget to re-tighten the hold down when
you are finished. Now that we have verified the timing, we can
click clear on the handheld and the Sniper is now controlling ignition timing. Once the engine coolant has reached the temperature
of at least 160 degrees, we can adjust our idle speed to the RPMs that we selected in
the startup wizard. To do this, select the monitor icon from the
home screen, then multi-gauge, then finally the sensors tab. With the vehicle in neutral and the parking
brake applied, rotate the curve idle adjustment screw open or closed until the IAC reading
is between two and ten percent. If your TPS registers above zero, you’ll need
to cycle the ignition switch, turning the engine off, then back on to reset the TPS
back to zero. Now that the idle is set, we can install the
factory air cleaner. Install the new sealing gasket included in
the kit onto the throttle body, then align the air cleaner assembly on the studs and
tighten both wingnuts. Attach the fresh air duct and you are finished. Congratulations, with the stock air cleaner,
installed, you are now ready to hit the road and let Sniper self-tune while you enjoy the
drive. Don’t forget to refer to our quick start guide
and follow the instructions found under the first drive section. Try to perform your first drive in an area
without too much traffic and if you can take a friend along, they can concentrate on the
gauges while you focus on the driving. Thanks for watching, to see more great how-to
videos, visit our website at SniperEFI.com

11 thoughts on “How To Install Sniper EFI BBD for 1971-1986 Jeep CJs

  1. This is cool, but retains all the exhaust pulse tubing and vacuum lines. I am very happy to get rid of all that rusted out junk….but now comes the smog test…..

  2. Installed the Sniper EFI but my smog tubing is blocking the fuel inlet, which 90 degree fitting should i use in place of the one that came with the kit? Is it part number #98220berl?

  3. Installed the Sniper EFI but my smog tubing is blocking the fuel inlet, which 90 degree fitting should i use in place of the one that came with the kit? Is it part number #98220berl?

  4. I want to get this for my 1990 YJ but I have a few concerns.
    1) Are you guys working on getting this CARB compliant for California?
    2) I plan on keeping my Pulse Tube for CA smog. Do you guys have any instructions on disconnecting pins no longer needed for the MCU?

    3) Do you have a cover plate so I can remove the mechanical fuel pump?

    Do you carry a 20 gal tank and pickup as well?

    Please include our ugly stepchild ‘87-‘90 YJ’s with Carburetors and smog crap.

  5. I am thinking about getting this for a -75 AMC Pacer with a 258. Apart from my intake being a single barrel, is there anything else I should worry about?

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