1994 JEEP CHEROKEE spark plugs

²Inspect secondary ignition system components:
wire routing and condition, distributor cap and rotor,
ignition coil, spark plugs. Reroute or replace as re-
quired.RADIO ILLUMINATION RELAY
XJ
The radio illumination relay is in the relay center.
The relay center is located on the lower instrument
panel trim cover, right of the steering column
(Fig. 2).
YJ
The radio illumination relay is taped to the har-
ness above the radio.
RADIO CONNECTOR PINS
Fig. 2 Radio Illumination Relay
JAUDIO SYSTEMS 8F - 3

can easily be wiped off. Components should be
torqued in place within 15 minutes. The use of a lo-
cating dowel is recommended during assembly to pre-
vent smearing the material off location.
ENGINE PERFORMANCE
To provide best vehicle performance and lowest ve-
hicle emissions, it is most important that the tune-up
be done accurately. Use the specifications listed on
the Vehicle Emission Control Information label
found on the engine compartment hood.
(1) Test battery specific gravity. Add water, if nec-
essary. Clean and tighten battery connections.
(2) Test cranking amperage draw (refer to Group
8B, Battery/Starter Service for the proper proce-
dures).
(3) Tighten the intake manifold bolts (refer to
Group 11, Exhaust System and Intake Manifold for
the proper specifications).
(4) Perform cylinder compression test:
(a) Check engine oil level and add oil, if neces-
sary.
(b) Drive the vehicle until engine reaches normal
operating temperature.
(c) Select a route free from traffic and other
forms of congestion, observe all traffic laws and
briskly accelerate through the gears several times.
The higher engine speed may help clean out valve
seat deposits which can prevent accurate compres-
sion readings.
CAUTION: DO NOT overspeed the engine.
(d) Remove all spark plugs from engine. As
spark plugs are being removed, check electrodes for
abnormal firing indicators - fouled, hot, oily, etc.
Record cylinder number of spark plug for future
reference.
(e) Disconnect coil wire from distributor and se-
cure to good ground to prevent a spark from start-
ing a fire.
(f) Be sure throttle blades are fully open during
the compression check.
(g) Insert compression gage adaptor into the
No.1 spark plug hole. Crank engine until maxi-
mum pressure is reached on gauge. Record this
pressure as No.1 cylinder pressure.
(h) Repeat Step 4g for all remaining cylinders.
(i) Compression should not be less than 689 kPa
(100 psi) and not vary more than 172 kPa (25 psi)
from cylinder to cylinder.
(j) If cylinder(s) have abnormally low compres-
sion pressures, repeat steps 4a through 4h.
(k) If the same cylinder(s) repeat an abnormally
low reading, it could indicate the existence of a
problem in the cylinder.
The recommended compression pressures are
to be used only as a guide to diagnosing engineproblems. An engine should NOT be disassem-
bled to determine the cause of low compression
unless some malfunction is present.
(5) Clean or replace spark plugs as necessary. Ad-
just gap (refer to Group 8D, Ignition System for gap
adjustment and torque).
(6) Test resistance of spark plug cables (refer to
Group 8D, Ignition System).
(7) Inspect the primary wire. Test coil output volt-
age, primary and secondary resistance. Replace parts
as necessary (refer to Group 8D, Ignition System and
make necessary adjustment).
(8) Set ignition timing to specifications (refer to
Specification Label on engine compartment hood).
(9) Perform a combustion analysis.
(10) Test fuel pump for pressure and vacuum (refer
to Group 14, Fuel System for the proper specifica-
tions).
(11) Inspect air filter element (refer to Group 0,
Lubrication and Maintenance for the proper proce-
dure).
(12) Inspect crankcase ventilation system (refer to
Group 0, Lubrication and Maintenance for the proper
procedure).
(13) For emission controls refer to Group 25, Emis-
sion Controls System for service procedures.
(14) Inspect and adjust accessory belt drives (refer
to Group 7, Cooling System for the proper adjust-
ments).
(15) Road test vehicle as a final test.
HONING CYLINDER BORES
Before honing, stuff plenty of clean shop towels un-
der the bores and over the crankshaft to keep abra-
sive materials from entering the crankshaft area.
(1) Used carefully, the Cylinder Bore Sizing Hone
C-823 equipped with 220 grit stones, is the best tool
for this job. In addition to deglazing, it will reduce
taper and out-of-round as well as removing light
scuffing, scoring or scratches. Usually a few strokes
will clean up a bore and maintain the required lim-
its.
CAUTION: DO NOT use rigid type hones to remove
cylinder wall glaze.
(2) Deglazing of the cylinder walls may be done if
the cylinder bore is straight and round. Use a cylin-
der surfacing hone, Honing Tool C-3501, equipped
with 280 grit stones (C-3501-3810). 20-60 strokes, de-
pending on the bore condition, will be sufficient to
provide a satisfactory surface. Using honing oil
C-3501-3880 or a light honing oil available from ma-
jor oil distributors.
CAUTION: DO NOT use engine or transmission oil,
mineral spirits or kerosene.
9 - 2 ENGINESJ

CONNECTING ROD BEARING CLEARANCE
Engine connecting rod bearing clearances can be
determined by use of Plastigage, or equivalent. The
following is the recommended procedures for the use
of Plastigage:
(1) Remove oil film from surface to be checked.
Plastigage is soluble in oil.
(2) Place a piece of Plastigage across the entire
width of the bearing cap shell (Fig. 2). Position the
Plastigage approximately 6.35 mm (1/4 inch) off cen-
ter and away from the oil holes. In addition, suspect
areas can be checked by placing the Plastigage in the
suspect area.
(3) The crankshaft must be turned until the con-
necting rod to be checked starts moving toward the
top of the engine. Only then should the rod cap with
Plastigage in place be assembled. Tighten the rod
cap nut to 45 Nzm (33 ft. lbs.) torque.DO NOT ro-
tate the crankshaft or the Plastigage may be
smeared, giving inaccurate results.
(4) Remove the bearing cap and compare the width
of the flattened Plastigage with the scale provided on
the package (Fig. 3). Plastigage generally comes in 2
scales (one scale is in inches and the other is a met-
ric scale). Locate the band closest to the same width.
This band shows the amount of clearance. Differ-
ences in readings between the ends indicate the
amount of taper present. Record all readings taken
(refer to Engine Specifications).
(5) Plastigage is available in a variety of clearance
ranges. The 0.025-0.076 mm (0.001-0.003 inch) range
is usually the most appropriate for checking engine
bearing clearances.
REPAIR DAMAGED OR WORN THREADS
Damaged or worn threads can be repaired. Essen-
tially, this repair consists of:
²Drilling out worn or damaged threads.
²Tapping the hole with a special Heli-Coil Tap, or
equivalent.
²Installing an insert into the tapped hole.
This brings the hole back to its original thread size.
CAUTION: Be sure that the tapped holes maintain
the original center line.Heli-Coil tools and inserts are readily available
from automotive parts jobbers.
SERVICE ENGINE ASSEMBLY (SHORT BLOCK)
A service replacement engine assembly (short
block) may be installed whenever the original cylin-
der block is defective or damaged beyond repair. It
consists of the cylinder block, crankshaft, piston and
rod assemblies. If needed, the camshaft must be pro-
cured separately and installed before the engine is
installed in the vehicle.
A short block is identified with the letter ``S'' stamped
on the same machined surface where the build date
code is stamped for complete engine assemblies.
Installation includes the transfer of components
from the defective or damaged original engine. Fol-
low the appropriate procedures for cleaning, inspec-
tion and torque tightening.
HYDROSTATIC LOCK
When an engine is suspected of hydrostatic lock
(regardless of what caused the problem), follow the
steps below.
(1) Perform the Fuel Pressure Release Procedure
(refer to Group 14, Fuel System).
(2) Disconnect the negative cable from the battery.
(3) Inspect air cleaner, induction system and in-
take manifold to ensure system is dry and clear of
foreign material.
(4) Place a shop towel around the spark plugs to
catch any fluid that may possibly be under pressure in
the cylinder head. Remove the plugs from the engine.
CAUTION: DO NOT use the starter motor to rotate
the crankshaft. Severe damage could occur.
(5) With all spark plugs removed, rotate the crank-
shaft using a breaker bar and socket.
(6) Identify the fluid in the cylinders (i.e. coolant,
fuel, oil, etc.).
(7) Make sure all fluid has been removed from the
cylinders.
(8) Repair engine or components as necessary to
prevent this problem from occurring again.
(9) Squirt engine oil into the cylinders to lubricate
the walls. This will prevent damage on restart.
(10) Install new spark plugs. Tighten the spark
plugs to 37 Nzm (27 ft. lbs.) torque.
(11) Drain engine oil. Remove and discard the oil
filter.
(12) Install the drain plug. Tighten the plug to 34
Nzm (25 ft. lbs.) torque.
(13) Install a new oil filter.
(14) Fill engine crankcase with the specified
amount and grade of oil (refer to Group 0, Lubrica-
tion and Maintenance).
(15) Connect the negative cable to the battery.
(16) Start the engine and check for any leaks.
Fig. 3 Clearance Measurement
9 - 4 ENGINESJ

ENGINE DIAGNOSIS
Engine diagnosis is helpful in determining the
causes of malfunctions not detected and remedied by
routine tune-ups.
These malfunctions may be classified as either per-
formance (e.g., engine idles rough and stalls) or me-
chanical (e.g., a strange noise).
Refer to the Service DiagnosisÐPerformance chart
and the Service DiagnosisÐMechanical chart for pos-
sible causes and corrections of malfunctions. Refer to
Group 14, Fuel System for the fuel system diagnosis.
Additional tests and diagnostic procedures may be
necessary for specific engine malfunctions that can
not be isolated with the Service Diagnosis charts. In-
formation concerning additional tests and diagnosis
is provided within the following diagnosis:
²Cylinder Compression Pressure Test.
²Cylinder Combustion Pressure Leakage Test.
²Engine Cylinder Head Gasket Failure Diagnosis.
²Intake Manifold Leakage Diagnosis.
INTAKE MANIFOLD LEAKAGE DIAGNOSIS
An intake manifold air leak is characterized by
lower than normal manifold vacuum. Also, one or
more cylinders may not be functioning.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A DI-
RECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR THE FAN.
DO NOT WEAR LOOSE CLOTHING.
METHOD 1
(1) Start the engine.
(2) Open the acetylene valve of an oxyacetylene
torch. DO NOT ignite.
(3) Pass the torch tip over the exposed gasket area
(EDGE) between the manifold and the engine cylin-
der head.
(4) If the engine speed increases, the manifold has
an air leak.
METHOD 2
(1) Start the engine.
(2) Apply engine oil to the exposed gasket area
(EDGE) between the manifold and the engine cylin-
der head.
(3) If oil is forced into the manifold and if smoke is
visible from the exhaust tailpipe, the manifold has
an air leak.
CYLINDER COMPRESSION PRESSURE TEST
The results of a cylinder compression pressure test
can be utilized to diagnose several engine malfunc-
tions.
Ensure the battery is completely charged and the
engine starter motor is in good operating condition.Otherwise the indicated compression pressures may
not be valid for diagnosis purposes.
(1) Clean the spark plug recesses with compressed
air.
(2) Remove the spark plugs.
(3) Secure the throttle in the wide-open position.
(4) Disconnect the ignition coil.
(5) Insert a compression pressure gauge and rotate
the engine with the engine starter motor for three
revolutions.
(6) Record the compression pressure on the 3rd
revolution. Continue the test for the remaining cyl-
inders.
Refer to Engine Specifications for the correct en-
gine compression pressures.
ENGINE CYLINDER HEAD GASKET FAILURE
DIAGNOSIS
A leaking engine cylinder head gasket usually re-
sults in loss of power, loss of coolant and engine mis-
firing.
An engine cylinder head gasket leak can be located
between adjacent cylinders or between a cylinder and
the adjacent water jacket.
²An engine cylinder head gasket leaking between
adjacent cylinders is indicated by a loss of power
and/or engine misfire.
²An engine cylinder head gasket leaking between a
cylinder and an adjacent water jacket is indicated by
coolant foaming or overheating and loss of coolant.
CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is
leaking between adjacent cylinders; follow the proce-
dures outlined in Cylinder Compression Pressure
Test. An engine cylinder head gasket leaking be-
tween adjacent cylinders will result in approximately
a 50-70% reduction in compression pressure.
CYLINDER-TO-WATER JACKET LEAKAGE
TEST
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A DI-
RECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR THE FAN.
DO NOT WEAR LOOSE CLOTHING.
Remove the radiator cap.
Start the engine and allow it to warm up until the
engine thermostat opens.
If a large combustion/compression pressure leak ex-
ists, bubbles will be visible in the coolant.
If bubbles are not visible, install a radiator pres-
sure tester and pressurize the coolant system.
JENGINES 9 - 5

If a cylinder is leaking combustion pressure into
the water jacket, the tester pointer will pulsate with
every combustion stroke of the cylinder.
CYLINDER COMBUSTION PRESSURE LEAKAGE
TEST
The combustion pressure leakage test provides an
accurate means for determining engine condition.
Combustion pressure leakage testing will detect:
²Exhaust and intake valve leaks (improper seat-
ing).
²Leaks between adjacent cylinders or into water
jacket.
²Any causes for combustion/compression pressure
loss.
WARNING: DO NOT REMOVE THE RADIATOR CAP
WITH THE SYSTEM HOT AND UNDER PRESSURE
BECAUSE SERIOUS BURNS FROM COOLANT CAN
OCCUR.
Check the coolant level and fill as required. DO
NOT install the radiator cap.
Start and operate the engine until it attains nor-
mal operating temperature, then turn the engine
OFF.Remove the spark plugs.
Remove the oil filler cap.
Remove the air cleaner.
Calibrate the tester according to the manufactur-
er's instructions. The shop air source for testing
should maintain 483 kPa (70 psi) minimum, 1 379
kPa (200 psi) maximum and 552 kPa (80 psi) recom-
mended.
Perform the test procedures on each cylinder ac-
cording to the tester manufacturer's instructions.
While testing, listen for pressurized air escaping
through the throttle body, tailpipe and oil filler cap
opening. Check for bubbles in the radiator coolant.
All gauge pressure indications should be equal,
with no more than 25% leakage.
FOR EXAMPLE:At 552 kPa (80 psi) input pres-
sure, a minimum of 414 kPa (60 psi) should be main-
tained in the cylinder.
Refer to the Cylinder Combustion Pressure Leak-
age Test Diagnosis chart.
CYLINDER COMBUSTION PRESSURE LEAKAGE TEST DIAGNOSIS
9 - 6 ENGINESJ

(a) Remove the bolts from the A/C compressor
mounting bracket and set the compressor aside.
(b) Remove the air conditioner compressor
bracket bolts from the engine cylinder head.
(c) Loosen the through bolt at the bottom of the
bracket.
(9) If equipped, disconnect the power steering
pump bracket. Set the pump and bracket aside. DO
NOT disconnect the hoses.
(10) Remove the fuel lines and vacuum advance
hose.
(11) Remove the intake and engine exhaust mani-
folds from the engine cylinder head (refer to Group
11, Exhaust System and Intake Manifold for the
proper procedures).
(12) Disconnect the ignition wires and remove the
spark plugs.
(13) Disconnect the temperature sending unit wire
connector.
(14) Remove the ignition coil and bracket assem-
bly.
(15) Remove the engine cylinder head bolts.
(16) Remove the engine cylinder head and gasket
(Fig. 3).
(17) If this was the first time the bolts were re-
moved, put a paint dab on the top of the bolt. If the
bolts have a paint dab on the top of the bolt or it
isn't known if they were used before, discard the
bolts.
(18) Stuff clean lint free shop towels into the cyl-
inder bores.
CLEANING
Thoroughly clean the engine cylinder head and cyl-
inder block mating surfaces. Clean the intake and
exhaust manifold and engine cylinder head mating
surfaces. Remove all gasket material and carbon.
Check to ensure that no coolant or foreign material
has fallen into the tappet bore area.
Remove the carbon deposits from the combustion
chambers and top of the pistons.
INSPECTION
Use a straightedge and feeler gauge to check the
flatness of the engine cylinder head and block mat-
ing surfaces.
INSTALLATION
The engine cylinder head gasket is a composition
gasket. The gasket is to be installed DRY.DO NOT
use a gasket sealing compound on the gasket.
If the engine cylinder head is to be replaced and
the original valves used, measure the valve stem di-
ameter. Only standard size valves can be used with a
service replacement engine cylinder head unless the
replacement head valve stem guide bores are reamed
to accommodate oversize valve stems. Remove all
carbon buildup and reface the valves.
(1) Fabricate two engine cylinder head alignment
dowels from used head bolts (Fig. 4). Use the longest
head bolt. Cut the head of the bolt off below the hex
head. Then cut a slot in the top of the dowel to allow
easier removal with a screwdriver.
(2) Install one dowel in bolt hole No.10 and the
other dowel in bolt hole No.8 (Fig. 5).
(3) Remove the shop towels from the cylinder
bores. Coat the bores with clean engine oil.
(4) Place the engine cylinder head gasket (with the
numbers facing up) over the dowels.
Fig. 3 Engine Cylinder Head Assembly
Fig. 4 Fabricate Alignment Dowels
Fig. 5 Alignment Dowel Locations
9 - 20 2.5L ENGINEJ

(5) Place the engine cylinder head over the dowels.
CAUTION: Engine cylinder head bolts should be re-
used only once. Replace the head bolts if they were
used before or if they have a paint dab on the top
of the bolt.
(6) Coat the threads of bolt No.7, only, with Loctite
PST sealant or equivalent.
(7) Install all head bolts, except No.8 and No.10.
(8) Remove the dowels.
(9) Install No.8 and No.10 head bolts.
(10) Tighten the engine cylinder head bolts in se-
quence according to the following procedure (Fig. 6):
(a) Tighten all bolts in sequence (1 through 10)
to 30 Nzm (22 ft. lbs.) torque.
(b) Tighten all bolts in sequence (1 through 10)
to 61 Nzm (45 ft. lbs.) torque.
(c) Check all bolts to verify they are set to 61
Nzm (45 ft. lbs.) torque.
(d) Tighten bolts (in sequence):
²Bolts 1 through 6 to 149 Nzm (110 ft. lbs.) torque.
²Bolt 7 to 136 Nzm (100 ft. lbs.) torque.
²Bolts 8 through 10 to 149 Nzm (110 ft. lbs.) torque.
CAUTION: During the final tightening sequence,
bolt No.7 will be tightened to a lower torque than
the rest of the bolts. DO NOT overtighten bolt No.7.
(e) Check all bolts in sequence to verify the cor-
rect torque.
(f) If not already done, clean and mark each bolt
with a dab of paint after tightening. Should you
encounter bolts which were painted in an earlier
service operation, replace them.
(11) Install the ignition coil and bracket assembly.
(12) Connect the temperature sending unit wire
connector.
(13) Install the spark plugs and tighten to 37 Nzm
(27 ft. lbs.) torque. Connect the ignition wires.(14) Install the intake and exhaust manifolds (re-
fer to Group 11, Exhaust System and Intake Mani-
fold for the proper procedures).
(15) Install the fuel lines and the vacuum advance
hose.
(16) If equipped, attach the power steering pump
and bracket.
(17) Install the push rods, rocker arms, pivots and
bridges in the order they were removed.
(18) Install the engine cylinder head cover.
(19) Attach the air conditioning compressor mount-
ing bracket to the engine cylinder head and block.
Tighten the bolts to 40 Nzm (30 ft. lbs.) torque.
(20) Attach the air conditioning compressor to the
bracket. Tighten the bolts to 27 Nzm (20 ft. lbs.)
torque.
CAUTION: The serpentine drive belt must be routed
correctly. Incorrect routing can cause the water
pump to turn in the opposite direction causing the
engine to overheat.
(21) Install the serpentine drive belt and correctly
tension the belt (refer to Group 7, Cooling System for
the proper procedure).
(22) Install the air cleaner and ducting.
(23) Install the engine cylinder head cover.
(24) Connect the hoses to the thermostat housing
and fill the cooling system to the specified level (re-
fer to Group 7, Cooling Systems for the proper proce-
dure).
(25) The automatic transmission throttle linkage
and cable must be adjusted after completing the en-
gine cylinder head installation (refer to Group 21,
Transmissions for the proper procedures).
(26) Install the temperature sending unit and con-
nect the wire connector.
(27) Connect the fuel pipe and vacuum advance
hose.
(28) Connect negative cable to battery.
(29) Connect the upper radiator hose and heater
hose at the thermostat housing.
(30) Fill the cooling system. Check for leaks.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN DIRECT
LINE WITH THE FAN. DO NOT PUT HANDS NEAR
THE PULLEYS, BELTS OR FAN. DO NOT WEAR
LOOSE CLOTHING.
(31) Operate the engine with the radiator cap off.
Inspect for leaks and continue operating the engine
until the thermostat opens. Add coolant, if required.
VALVE SPRINGS AND OIL SEALS
This procedure can be done with the engine cylin-
der head installed on the block.
Fig. 6 Engine cylinder head Bolt Tightening
Sequence
J2.5L ENGINE 9 - 21

least 1 600 km (1,000 miles). The oil supplement
need not be drained until the next scheduled oil
change.
(7) Install the engine cylinder head cover.
VALVE TIMING
Disconnect the spark plug wires and remove the
spark plugs.
Remove the engine cylinder head cover.
Remove the capscrews, bridge and pivot assembly,
and rocker arms from above the No.1 cylinder.
Alternately loosen each capscrew, one turn at a
time, to avoid damaging the bridge.
Rotate the crankshaft until the No.4 piston is at
top dead center (TDC) on the compression stroke.
Rotate the crankshaft counterclockwise (viewed
from the front of the engine) 90É.
Install a dial indicator on the end of the No.1 cyl-
inder intake valve push rod. Use rubber tubing to se-
cure the indicator stem on the push rod.
Set the dial indicator pointer at zero.
Rotate the crankshaft clockwise (viewed from the
front of the engine) until the dial indicator pointer
indicates 0.305 mm (0.012 inch) travel distance (lift).
The timing notch index on the vibration damper
should be aligned with the TDC mark on the timing
degree scale.
If the timing notch is more than 13 mm (1/2 inch)
away from the TDC mark in either direction, the
valve timing is incorrect.
If the valve timing is incorrect, the cause may be a
broken camshaft pin. It is not necessary to replace
the camshaft because of pin failure. A spring pin is
available for service replacement.
VIBRATION DAMPER
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove the serpentine drive belt and fan
shroud.
(3) Remove the vibration damper retaining bolt
and washer.
(4) Use Vibration Damper Removal Tool 8068 to
remove the damper from the crankshaft (Fig. 1).
INSTALLATION
(1) Apply Mopar Silicone Rubber Adhesive Sealant
to the keyway in the crankshaft and insert the key.
With the key in position, align the keyway on the vi-
bration damper hub with the crankshaft key and tap
the damper onto the crankshaft.
(2) Install the vibration damper retaining bolt and
washer.
(3) Tighten the damper retaining bolt to 108 Nzm
(80 ft. lbs.) torque.(4) Install the serpentine drive belt and tighten to
the specified tension (refer to Group 7, Cooling Sys-
tems for the proper specifications and procedures).
(5) Connect negative cable to battery.
TIMING CASE COVER OIL SEAL REPLACEMENT
This procedure is done with the timing case cover
installed.
(1) Disconnect negative cable from battery.
(2) Remove the serpentine drive belt.
(3) Remove the vibration damper.
(4) Remove the radiator shroud.
(5) Carefully remove the oil seal (Fig. 2). Make
sure seal bore is clean.
(6) Position the replacement oil seal on Timing
Case Cover Alignment and Seal Installation Tool
6139 with seal open end facing inward. Apply a light
film of Perfect Seal, or equivalent, on the outside di-
ameter of the seal. Lightly coat the crankshaft with
engine oil.
(7) Position the tool and seal over the end of the
crankshaft and insert a draw screw tool into Seal In-
stallation Tool 6139 (Fig. 3). Tighten the nut against
the tool until it contacts the cover.
Fig. 1 Vibration Damper Removal Tool 8068
Fig. 2 Timing Case Cover Oil Seal Removal
9 - 26 2.5L ENGINEJ