HESCO Supercharger installation instructions for a 1993 ZJ (Grand
Version 1.2 - November 11, 1998
Note These instructions are derived from the original
HESCO instructions. They have been modified by me based on the problems
I have encountered in the installation process. Even that does not guarantee
I didnít miss something. Read both sets, it canít hurt. Douglas W. Wilson.
THINGS YOU WILL NEED!
Jeep Service Manual (for torque specs etc.)
Torque Wrench (for the pulley, and other bolts)
Deep well 10mm for the throttle body
Small set of wrenches for the casting
Set of allen keys for the casting
5/16 hex drive for the superchargers bolts
T-50 Torx bit if you have to take the seatbelts off to run the boost-a-pump
Bottle of power steering fluid
¼ inch plastic vacuum T fitting
¼ inch plastic vacuum splice
A few nice days, an understanding friend , and a spare vehicle just
in caseÖ J
1 - Remove rubber air duct from throttle body, unclamp air-box hat to expose
air filter, unplug the two breather lines from the air-box hat and remove
the duct and air-box had as a unit.
2 - Loosen the power steering pump and remove the drive belt and top pivot
bolt. Next remove the long 3/8" mounting bolt just to the left of the pivot
bolt. Remove the power steering pump. And reservoir.
3 - Disconnect the fittings and remove the throttle body. (NOTE: stuffing
a rag in the hole keeps things from falling in)
4 - Remove the bracket that holds the throttle body and transmission cables
from the intake manifold.
5 - Remove all five of the vacuum fittings from the intake manifold (one
at the front, four at the rear, and one where the brake booster ties in
by the throttle body).
6 - Relocate the MAP sensor fitting to the rear most hole. (MAP sensor
is the one mounted to the fire wall just behind the intake manifold)
7 - Move the MAP sensor rearward and attach it to the brake line using
the two larger tie wraps provided. You will have to pull 3 or 4 inches
of wire out of the harness to make it fit.
8 - Splice the pressure sensor included in the boost-a-pump kit into the
MAP sensor line I used the connector from the front (the one with two pipes)
so I could mount the MAP and Boost-a-Pump sensor to it.
9 - Relocate the MAT sensor (the one that has wires) to the intake side
of the super charger. (same side as the throttle body)
10 - Use the plugs from the supercharger to plug the remaining rearward
holes in the intake manifold. Leave the front hole open for now.
11 - Put the brake vacuum attachment in the hole to the drivers side of
the supercharger and fill out the remainder with the smaller attachments.
12 - Remove the center valve cover bolt from the passenger side of the
valve cover and the one just forward of it. (the third and fourth bolt
from the front)
13 - Uncap the valve on the fuel rail and relieve the fuel pressure.
GASOLINE IS HAZARDOUS, WEAR EYE PROTECTION AND NEVER WORK ON A HOT
ENGINE OR AROUND FIRE OR FLAME. THE FUEL IN THE ZJ IS UNDER PRESSURE ALL
14 - Unplug the RETURN fuel line from the fuel rail. (This is the line
that connects to the pressure regulator on the forward end of the fuel
TEST FIT THE SUPERCHARER!
1 - Locate and run the Kenne-Bell boost-a-pump electronics. (The wire is
14 Gauge Orange with a Black stripe and exits the vehicle just under the
rear seat to the left of the seat latch. You can see where it goes out
by looking under the vehicle just forward of the fuel tank) If you donít
have room under the seat, remove the plastic door just aft of the tire
carrier and there should be a metal brace that will accommodate the electronics)
(If you have to extend the power wires use 10 Gauge stranded)
2 - Locate the control head for the boost-a-pump (just under the dash left
of the VIC is a good spot)
3 - Run the wire with the RCA plug to the control head.
4 - Run the wire with the two spade terminals through the bulkhead plug.
(up just to the right of where the accelerator cable exits)
5 - Put the fuel warning stickers on (one by the fuel gauge and the other
by the filler)
6 - Install the wedge shaped adapter onto the intake manifold with one
of the new gaskets. Put Locktite on the bolts and torque to 120 inch pounds.
7 - Replace the stock steering pump reservoir with the one provided. Reattach
the pressure line and orient it so it is tight to the back of the reservoir.
8 - Install the new throttle body on the superchargers intake manifold
using the new gasket and fasteners supplied. Orient the throttle body so
that the linkage will be on the passenger side of the vehicle (right side).
(note. If the ear on the left side of the vacuum port isnít trimmed back
it will hit the valve cover. Check fit the supercharger and trim the throttle
body as required)
9 - Install the two aluminum stands into the valve cover bolt holes. (NOTE:
One is shorter to go through the spark plug wire loom) and bolt the throttle
linkage bracket provided. (The two short legs should be up). (in my case
one wasnít shorter, so I added washers to take up the extra space. Or you
could cut it.)
10 - Replace the idler to the right of the A/C compressor with the one
supplied in the kit. (if required)
Mark where it aligns
then come back here and follow the directions with the anaerobic
10 - Install the supercharger assembly onto the engine using the anaerobic
sealer between the mating surfaces. (DO NOT TIGHTEN THE BOLTS TILL INSTRUCTED
TO DO SO.)
11 - Install the front compressor shaft brace over the compressor shaft
and the front left head bolt. (Donít take the existing bolt off) Attach
with the nut provided and reinstall the power steering pump with the long
8mm bolt that replaces the power steering pump pivot bolt. Install the
long 3/8" countersunk mounting bolt in the power steering pump bracket
and through the lower hole in the compressor shaft brace. Tighten the set
screw in the brace where it slips over the compressor shaft.
12 - Install the new drive belt provided. Route the belt as shown below.
Back off all adjustment on the power steering pump. The new idler has an
eccentric shaft. Adjust this shaft for maximum contact with the power steering
pump and tighten the bolt to 30 foot pounds. Tighten the belt to stock
13 - Install the throttle cable, cruise control cable, and transmission
cable into this bracket and attach to the throttle body.
If the throttle plate is open a bit then your supercharger isnít
forward enough. Loosen the bolts under the supercharger and the set screw
and slide it forward if possible.
MARK where everything aligns, go back to step 10 and use the
(NOW, TIGHEN THE BOLTS ON THE SUPERCHARGER MOUNTING BRACKET)
14 - Install the fuel pressure regulator by attaching the black female
connector (on the regulator) to the same port you disconnected the fuel
bypass line from. Clamp the regulator to the injector fuel rail with the
¾" clamp on the regulator bracket. Attach the original female connector
to the short line. Install the ¼-90 fitting in the front port of
the stock intake manifold (under the supercharger shaft). Connect the small
line on the back of the fuel pressure regulator to the 4-way plastic connector.
Attach the fitting, stock regulator, and new regulator with the vacuum
hose and 4-way connector provided. (NOTE: The extra connector is for a
boost gauge of your choice) (Youíll need a shorter female line. If the
regulator doesnít have one call HESCO)
15 - Remove the air filter element and the rear most screw from the bottom
of the box. Tilt the box up and install the 1" spacer underneath. Replace
the bolt with the longer bolt provided and tighten. Now here is where I
made a small change to get things to fit better. I cut the 1" spacer to
¾" and used the remaining ¼" under the left most bolt at
the front. This provided a little more clearance and allowed the hood to
16 - Take the 6" piece of wire reinforced hose and slip it inside the stock
accordion duct. (NOTE: This is necessary to keep the stock duct from collapsing
under full acceleration)
17 - Reinstall the duct on the air box lid using the stock clamp.
18 - Connect the duct to the throttle body with the plastic S pipe and
3" piece of red silicon pipe. (Yes, it goes over the superchargers drive
shaft, and yes, youíll have to squash it a bit to get it to fit right.)
19 - Use the 1/8" vacuum line supplied to reconnect the vapor canister
to a vacuum source at the rear of the supercharger.
20 - Make sure you have removed the sealant from the vent on the front
shaft of the supercharger. (there is a little tag there to remind you also)
21 - Close your hood and note where the top of the pulley makes a mark
on the hood insulation. Cut this away with a hobby knife. Cut a section
about 3" by 3"
1 - Turn the adjustment on the boost-a-pump all the way to lean and then
back toward rich by ¼ turn.
2 - Start the engine and IMMEDIATELY CHECK FOR LEAKS
3 - Test drive and then RECHECK ALL BOLTS AND RETENSION THE BELT, check
the insulation under the hood for rubbing and trim as necessary.
4 - If you get knocking, adjust the boost-a-pump slightly toward the rich
side. If you donít, lean it out a bit. This will take a while to get right.
Service the compressor with MOBILE 1 oil at 12,000 mile intervals. Add
oil as required.
Check oil when you check your motor oil (every 3,000 miles is a good
The supercharger only takes 6 ounces of oil (DONíT OVERFILL IT OR YOUíLL
To drain, Remove the upper 1/8" pipe plug, then the lower 1/8" pipe
To fill, Replace the lower plug and add 6 ounces of oil then replace
the upper plug.
There is a dipstick on the compressor. (Itís under the little black
knob on the top)