Engine Controls - Remove/install/overhaul Geo Storm I

INTRODUCTION

Removal, overhaul and installation procedures are covered in this article. If component removal and installation is primarily an unbolt and bolt on procedure, only a torque specification may be furnished.

REMOVAL & INSTALLATION

1. Disconnect negative battery cable. Remove distributor cap. (Scheme 1) Mark distributor-to-engine position and distributor rotor-to-distributor housing position for installation reference. Remove distributor harness connector and hold-down bolt. Remove distributor.
2. DO NOT rotate crankshaft with distributor removed or reference marks will be incorrect. To install distributor, use reference marks and reverse removal procedure.

INSTALLING DISTRIBUTOR AFTER ENGINE HAS BEEN CRANKED

1. Rotate crankshaft until No. 1 piston is at TDC. Ensure timing marks on crankshaft pulley and timing cover are aligned to TDC position.
2. Align distributor drive mark with housing mark, or turn distributor rotor to No. 1 spark plug terminal on cap and install distributor. Start engine and set timing to specification. See IGNITION TIMING in ADJUSTMENTS article in the ENGINE PERFORMANCE Section.

Scheme 1

Remove distributor cap and rotor. Remove screws holding pick-up coil to base plate. Disconnect pick-up coil/crank angle sensor connector and remove pick-up coil/crank angle sensor. To install, reverse removal procedure. Adjust air gap to specification. See PICK-UP COIL/CRANK ANGLE SENSOR AIR GAP table.

PICK-UP COIL/CRANK ANGLE SENSOR AIR GAP

FUEL SYSTEM PRESSURE RELEASE

1. Remove fuel filler cap to relieve tank pressure. Remove fuel pump relay from underhood relay center. Relay center is located on left side of engine compartment near battery. Start engine and let run until it stalls.
2. Engage starter for about 10 seconds to ensure fuel line pressure has dissipated. Turn ignition off. Slowly loosen fuel outlet fitting at fuel filter located at driver's side frame rail. Use shop towel to absorb fuel that escapes as fuel pressure is relieved. When fuel stops leaking, tighten line.

1. Relieve fuel system pressure. See FUEL SYSTEM PRESSURE RELEASE. Disconnect negative battery cable. Siphon or pump fuel from tank. Raise and support vehicle. Remove exhaust pipe from catalytic converter. Disconnect fuel tank sending unit and fuel pump wiring harness connectors. Disconnect all fuel tank hoses and vapor line.
2. Using suitable jack, support fuel tank. Remove fuel tank mounting bolts. Lower and remove tank from vehicle. Remove fuel pump mounting bolts. Disconnect wires and fuel hose from pump assembly. Pull pump away from pump bracket. Remove pump fuel filter. To install, reverse removal procedure.

Removal

1. Clean around injectors with carburetor cleaner and/or compressed air. Relieve fuel pressure. See FUEL SYSTEM PRESSURE RELEASE. Drain cooling system. Remove negative battery cable and air intake duct assembly. Remove throttle cables and brackets.
2. Label and remove all electrical connectors, and vacuum hoses from throttle body assembly. Remove coolant hoses from throttle body. Label and remove vacuum hoses and ground wires from intake plenum. Remove intake plenum support brackets. Remove intake plenum from induction port manifold.
3. Disconnect electrical harness connectors from injectors. Using a back-up wrench on fuel rail fitting and tubing wrench on fuel pressure line, disconnect fuel pressure line from fuel rail. CAUTION: DO NOT attempt to remove fuel rail inlet fitting. Fitting is staked in position in fuel rail and is NOT removable.
4. Disconnect fuel return line at pressure regulator. Remove fuel rail bolts and spacers. Remove fuel rail with injectors. Ensure injectors DO NOT fall out of fuel rail. If replacing injectors in fuel rail, replace all injector "O" rings and injector-to-rail retainer clips.

Inspection

Inspect all components for damage. Replace as required. Ensure intake mating surfaces are clean and smooth with no scratches.

Installation

To install, reverse removal procedure. Lubricate new injector "O" rings with engine oil before installation. Use NEW "O" rings, seals and retainers in fuel rail when installing fuel inlet line and pressure regulator. Ensure injectors are firmly seated into rail and intake port sockets.

1. O2 sensor is mounted in exhaust manifold or in exhaust pipe just below the exhaust header. Sensor is equipped with a permanent pigtail which must be protected from damage when sensor is being removed. Ensure sensor is free of contaminants, but avoid using cleaning solvents of any type.
2. Sensor may be difficult to remove when engine temperature is less than 120°F (49°C). If O2 sensor is difficult to remove, use rust penetrant to avoid possible damage to exhaust manifold threads. Discard O2 sensor if contaminated.
3. Always use anti-seize compound on threads prior to installation of new sensor. New sensor comes precoated with anti-seize. DO NOT remove anti-seize from sensor. Tighten O2 sensor to 30 ft. lbs. (41 N.m).

1. Disconnect negative battery cable. Remove air cleaner assembly and air intake duct. Disconnect and label all vacuum hoses, wire connectors and cable linkages from throttle body.
2. Partially drain cooling system. Remove coolant hoses from throttle body. Remove bolts retaining throttle body to intake chamber. Remove throttle body and discard gasket. Clean gasket mating surfaces. DO NOT scratch mated sealing surfaces when removing old gasket material.
3. To install, reverse removal procedure. Use new gasket for reassembly. DO NOT use sealer on gasket. Tighten 4 throttle body-to-intake chamber bolts to specification. See TORQUE SPECIFICATIONS table at end of article. Refill cooling system

THROTTLE POSITION SENSOR (TPS)

Note. DO NOT immerse diaphragms, electrical components, or synthetic parts in carburetor cleaner.

1. With ignition off, remove air cleaner assembly (if necessary). Disconnect TPS harness connector and remove mounting screws.
2. To install, mount TPS to throttle body with alignment slots slightly counterclockwise of body holes. Then turn TPS clockwise to align holes and install mounting screws finger tight. Adjust TPS. See THROTTLE POSITION SENSOR (TPS) in ADJUSTMENTS article in the ENGINE PERFORMANCE Section.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS