This Chilton DIY repair manual, covers 1984-2001 Jeep 4x4 vehicles, including the following U.S. and Canadian models:
- Jeep Cherokee
- Jeep Grand Cherokee, 1993-1998
- Jeep Comanche
- Jeep Wagoneer
- Jeep Grand Wagoneer, 1993 only
ENGINE AND ENGINE OVERHAUL
TIMING CHAIN COVER AND SEAL | 4.0L ENGINE
(See figures 98 and 99)
- Remove the drive belts, engine fan and hub assembly, the accessory pulley and vibration damper.
- Remove the air conditioning compressor and alternator bracket assembly and set it aside. Don?t disconnect the refrigerant lines.
- Remove the oil pan to timing chain cover screws and the screws that attach the cover to the block.
- Raise the timing chain cover just high enough to detach the retaining nibs of the oil pan neoprene seal from the bottom side of the cover. This must be done to prevent pulling the seal end tabs away from the tongues of the oil pan gaskets, which could cause a leak.
- Remove the timing chain cover and gasket from the engine. Make sure the timing chain tensioner spring and thrust pin do not fall out of the preload bolt.
- Use a razor blade to cut off the oil pan seal end tabs flush with the front face of the cylinder block and remove the seal. Clean the timing chain cover, oil pan, and cylinder block surfaces.
- Remove the crankshaft oil seal from the timing chain cover. Thoroughly clean the mating surfaces.
- Apply RTV gasket material to both sides of the new gasket and position the gasket on the block.
- Cut the end tabs off of the replacement oil pan side gaskets, corresponding to those cut off of the original gasket. Cement the end tabs to the oil pan.
- Coat the front cover end tab recesses with a generous amount of RTV gasket sealant and position the seal on the timing case cover. Apply a coat of clean engine oil to the seal-to-pan contact surfaces.
- Make sure the tension spring and thrust pin are in place in the preload bolt. Position the case cover on the block.
- Place cover alignment tool (J-22248) in the crankcase opening of the cover.
- Install the cover-to-block bolts and the oil pan-to-cover bolts. Tighten the cover-to-block bolts to 62 inch lbs. (7 Nm); the cover-to-pan bolts to 11 ft. lbs (15 Nm).
- Remove the alignment tool and position the seal on the tool with the lip facing outward.
- Apply a light coat of sealer on the outside diameter of the seal.
- Lightly coat the crankshaft with clean engine oil.
- Position the tool and seal over the end of the crankshaft and insert a screw tool into the seal installation tool.
- Tighten the nut against the tool until it contacts the cover.
- Remove the tools and apply a light coating of engine oil on the vibration damper hub contact surface of the seal.
- Install the damper.
- Install all other parts in reverse order of removal. Tighten the damper pulley bolts to 20 ft. lbs.
MULTI-PORT INJECTION SYSTEM
All 4.0L engines from 1987 and all other engines from 1991 employ a Multi-Port Fuel Injection (MFI) system. The MFI system injects fuel into the intake manifold above the intake valve port of each cylinder through separate injectors.
The fuel system consists of the fuel tank, electric fuel pump, fuel filter, fuel tubes, fuel hoses, vacuum hoses, throttle body, and the fuel injectors.
A fuel return system is used on all vehicles. The system consists of the fuel tubes and hoses that route fuel back to the fuel tank, except on 1996 and later models. Jeep vehicles for 1996 and later do not utilize a separate fuel return line from the engine to the tank; instead, fuel is returned through the fuel pump module and back into the tank through the fuel pressure regulator (1996) or fuel filter/pressure regulator (1997 and later).
The fuel tank assembly consists of the tank, fuel gauge sending unit/fuel pump assembly, filler vent tube, rollover valve and a pressure filler cap (on some models).
Another part of the fuel system is the evaporation control system, which is designed to reduce the emission of fuel vapors into the atmosphere. The description and function of the evaporative control system is found in Section 4.
Subject: Transportation: Automotive: 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001 Jeep Cherokee, Grand Cherokee, Limited, Comanche, Wagoneer Repair Manual. ISBN-10: 1563927101 | ISBN-13: 9781563927102 | Chilton 40602