4.0L Engine: Other Jeep Cherokee II рестайлинг

FUEL PRESSURE RELEASE

1. Remove fuel filler cap and open tank flap valve to relieve tank pressure. Remove fuel pump relay from Power Distribution Center (PDC). PDC is located in engine compartment near battery. Start and run engine until it stalls. Attempt restarting engine until it will no longer start. Turn ignition off. Unplug connector from any injector.
2. Connect an 18-gauge (or smaller) jumper between either injection terminal and positive battery terminal. Connect one end of a second jumper to remaining injector terminal.
3. Momentarily touch other end of second jumper to negative battery terminal (no more than 4 seconds). Place a rag or towel around quick-connect fitting located at fuel rail.
4. If vehicle is equipped with a single-tab type fitting, clean fitting of any debris. Press release tab on side of fitting to release pull tab. While pressing release tab on side of fitting, use a small screwdriver to pry up pull tab. Raise pull tab until it separates from quick-connect fitting. Discard old pull tab.
5. If vehicle is equipped with a 2-tab type fitting, clean fitting of any debris. Squeeze plastic retainer tabs against sides of quick-connect fitting and pull fitting.
6. If vehicle is equipped with a retainer ring type fitting, clean fitting of any debris. Firmly push fitting towards component being serviced while firmly pushing Black, plastic retainer ring into fitting. With plastic ring depressed, pull fitting from component.
7. If vehicle is equipped with latch clip, clean fitting of any debris. Using a screwdriver, pry up on and slide latch clip. Remove clip. Using Fuel Line Removal Tool (FIH-9055-1), release locking fingers in end of line. Pull fuel line from fuel rail. On all models, return fuel pump relay to PDC. CAUTION: Always replace "O" rings, spacers and retainers whenever fuel system quick-connect fittings are disconnected. Ensure fuel connections are secure by verifying that only retaining tabs protrude from connectors and by pulling on tubes to verify they are locked into place.

COOLING SYSTEM BLEEDING

Add coolant only when engine is cold. Fill radiator completely and install pressure cap. Fill reserve/overflow tank to FULL mark. Operate engine until it reaches normal operating temperature. Shut engine off and allow to cool. Recheck coolant level in reserve/overflow tank as necessary.

POWER STEERING BLEEDING

1. Fill pump to COLD level on dipstick and let fluid settle for at least 2 minutes. Start engine and let run for a few seconds, then turn engine off. Add fluid if necessary. Repeat procedure until fluid level remains constant after running engine.
2. Raise and support front wheels. Slowly turn steering wheel right and left, lightly contacting wheel stops. Turn wheel at least 20 times. Check fluid level and add if necessary.
3. Lower vehicle, start engine and turn steering wheel slowly from lock to lock. Stop engine, check fluid level and add if necessary. If fluid is extremely foamy or milky looking, allow vehicle to stand a few minutes and repeat bleeding procedure.

Note. On models with 4.0 L engine, front grill must be removed to access radiator draincock. Draining cooling system can be accomplished by removing drain plug from side of block as well as by loosening radiator draincock. Drain plug is located on lower left side of engine block. see scheme 1

CYLINDER HEAD

Note. On models with 4.0 L engine, front grill must be removed to access radiator draincock. Draining cooling system can be accomplished by removing drain plug from side of block as well as by loosening radiator draincock. Drain plug is located on lower left side of engine block. see scheme 1

WATER PUMP

Note. On models with 4.0 L engine, front grill must be removed to access radiator draincock. Draining cooling system can be accomplished by removing drain plug from side of block as well as by loosening radiator draincock. Drain plug is located on lower left side of engine block. see scheme 1

Cylinder Head Service

Inspect for cracks in combustion chambers, coolant passages, ports and exhaust valve seats. Using straightedge, check cylinder head for warpage across bolt holes and diagonals. Resurface or replace cylinder head if warpage exceeds specification or damage exists. See CYLINDER HEAD table under ENGINE SPECIFICATIONS.

Valve Springs

Use Valve Spring Tester (C-647 or J-22738-02) to test each valve spring. Measure free length of each valve spring. Replace valve springs that do not meet specification. See VALVES & VALVE SPRINGS table under ENGINE SPECIFICATIONS.

Valve Stem Oil Seals

Replace valve stem oil seals if they have deteriorated or whenever valves are serviced. Oil seals are marked INT and EXH for intake and exhaust valves, respectively.

Valve Guides

Measure diameter of valve guide approximately 3/8" (10 mm) from valve spring side of head, both parallel and at right angles to long axis of head. If difference between measurements exceeds .0025" (.063 mm), or if diameter exceeds specification by .003" (.08 mm), ream valve guide for oversize valve stem. Valve seats must be refaced after reaming valve guides. See CYLINDER HEAD table under ENGINE SPECIFICATIONS.

Valve Seats

Reface valve seats to specification. Remove only enough metal to provide smooth finish. Use tapered stones to obtain specified seat width. Seat width runout should not exceed .0025" (.063 mm) after refacing. See CYLINDER HEAD table under ENGINE SPECIFICATIONS.

Valves

Reface valves to specification. After refacing valve, at least .031" (.79 mm) margin must remain. Valve stem tip can be resurfaced and chamfered when worn. DO NOT remove more than .01" (.25 mm). See VALVES & VALVE SPRINGS table under ENGINE SPECIFICATIONS.

Rocker Arms

Inspect pivot and valve stem contact surfaces of each rocker arm. Replace any rocker arm that is scuffed, pitted, cracked or excessively worn.

Push Rods

Inspect push rods for excessive wear. If wear is excessive because of lack of oil, replace and inspect corresponding valve lifter for excessive wear. Roll push rods on a flat surface to check for straightness. Replace push rod and/or valve lifter, if necessary. If wear exists along length of push rod, inspect cylinder head for obstruction.

Fitting Pistons

See PISTON & ROD ASSEMBLY .

Piston Rings

Install piston rings. Ensure ring end gap and side clearance are within specification. Install compression rings with dot(s) on ring surface toward top of piston. DO NOT interchange compression rings. Top ring has shiny coating on outer sealing surface. Second ring has slight chamfer on bottom of inside edge. Position ring end gaps in specified area. Ring gaps may vary 20 degrees from positions illustrated. (Scheme 18) See PISTONS, PINS & RINGS table under ENGINE SPECIFICATIONS.

Scheme 18

Rod Bearings

1. Inspect bearings for wear or damage. Replace as necessary. Using Plastigage, check bearing clearance. See «CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS»(ref-2578-S38043308522000032000000) table under ENGINE SPECIFICATIONS. Bearings are available for standard and undersize applications.
2. If necessary, different size upper and lower bearings may be combined to obtain correct oil clearance. Lubricate bearing surfaces with oil before installation. Tighten bolts to specification. Check rod side play. Rotate crankshaft to ensure freedom of movement. See «TORQUE SPECIFICATIONS»(ref-2578-S28095226392000032000000) table. See «CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS»(ref-2578-S38043308522000032000000) table.

Note. Avoid combining bearing inserts in excess of .001" (.03 mm) difference in size. Odd size inserts must be on bottom (rod cap) side.

Crankshaft & Main Bearings

1. Inspect bearings for wear or damage. Replace as necessary. Using Plastigage, check bearing clearance. See «CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS»(ref-2578-S38043308522000032000000) table under ENGINE SPECIFICATIONS. Bearings are available in standard and undersize. If necessary, different size upper and lower bearings may be installed to obtain correct oil clearance. Lubricate bearings before installation. NOTE: If different size bearings are used, odd size bearings must all be uniform in location (upper or lower). DO NOT use bearings with a thickness difference exceeding .001" (.03 mm).
2. Install upper bearing inserts. Install bearing caps and lower inserts. Tighten bearing caps in 3 stages to specification. Rotate crankshaft to ensure freedom of movement after tightening each cap. See «TORQUE SPECIFICATIONS»(ref-2578-S28095226392000032000000) table. See «CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS»(ref-2578-S38043308522000032000000) table.

Thrust Bearing

Check crankshaft end play. If end play is not within specification, replace thrust bearing. If end play is still not within specification, replace crankshaft.

Cylinder Block

1. Thoroughly clean all gasket surfaces. Using a tap, clean head bolt holes. Clean oil gallery by blowing compressed air into oil filter adapter, filter by-pass, oil gallery and crankshaft oil feed holes.
2. Measure cylinder bore diameter crosswise to cylinder block about 1/2" below top of bore. Repeat measurement at bottom of bore. Subtract smaller diameter from larger diameter to determine taper. Repeat measurements for each cylinder.
3. Repeat measurements with measuring device rotated 120 degrees. Repeat this step for a total of 3 measurements. Cylinder out-of-round is difference between measurements. Repeat for each cylinder.
4. Bore and hone cylinders for oversize pistons if taper or out-of-round exceeds specification. Move hone up and down to provide a 60-degree crosshatch pattern. DO NOT use a rigid hone or exceed 10 strokes per cylinder. See «CYLINDER BLOCK»(ref-2578-S22758195542000032000000) table under ENGINE SPECIFICATIONS.

CRANKSHAFT JOURNAL IDENTIFICATION

CONNECTING ROD BEARING INSERT APPLICATION

MAIN BEARING FITTINGS (CRANKSHAFT JOURNALS)

CRANKSHAFT BEARING INSERT APPLICATION

Oil Pressure

Minimum oil pressure should be 13 psi (89.6 kPa) at 600 RPM. Normal oil pressure should be 37-75 psi (255-517 kPa) at greater than 1600 RPM. Oil pressure relief is 75 psi (517 kPa).

Scheme 19