Engine Controls - Remove/install/overhaul Geo Prizm pre-I

INTRODUCTION

Removal, overhaul and installation procedures (when given by manufacturer) 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.

FUEL SYSTEM PRESSURE RELEASE

ADJUSTMENTS

Note. For all on-vehicle adjustments not covered in this article, see ADJUSTMENTS article.

Removal & Installation

1. Disconnect negative battery cable. Scribe reference mark indicating distributor-to-engine position. Remove distributor cap. Scribe reference mark indicating distributor rotor-to-distributor housing position. Remove distributor harness connector and hold-down bolt. Lift out distributor.
2. DO NOT crank or turn engine 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. Remove No. 1 spark plug. Crank engine while holding finger over hole to feel compression stroke. Align timing marks of crankshaft pulley and timing cover 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 in engine. Start engine and set timing to specification. See IGNITION TIMING in ON-VEHICLE ADJUSTMENTS article.

(Scheme 1)and (Scheme 2).

Scheme 1

Scheme 2

Remove distributor cap and rotor. Remove screws holding pick-up coil to base plate. Unplug pick-up coil/crank angle sensor connector and remove. 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

1. Relieve fuel system pressure. See FUEL SYSTEM in BASIC TESTING article. Disconnect negative battery cable, fuel tank sending unit harness connector and fuel pump power wire connector. Disconnect all fuel tank hoses and vapor line.
2. Using suitable jack, support fuel tank and remove mounting straps. Lower tank to enable removal of pump screws and remove fuel pump assembly. Disconnect wires and fuel hose from pump. Pull pump away from pump bracket. Remove pump fuel filter and check for obstructions. To install, reverse removal procedure.

FUEL FILTER

Removal

1. Fuel filter is located in gas tank. Disconnect negative battery cable. Before removing fuel system parts, clean with a spray-type engine cleaner (AC-Delco X-30A or equivalent). Follow cleaner instructions but DO NOT soak system parts in liquid cleaning solvent.
2. Relieve fuel system pressure. See FUEL SYSTEM in BASIC TESTING article. Disconnect lower fitting (through left wheel well opening). Discard fitting gaskets.
3. Disconnect filter upper fitting. Discard fitting gaskets. Remove filter from retaining bracket. (Scheme 3) Remove filter from vehicle. (Scheme 4)

Note. Wrap shop cloth around fittings to collect fuel, then place cloth in an approved container. Cover the ends of the components to keep dirt and fuel in. Inspect sealing surfaces for hose fittings and bolts.

Scheme 3

Scheme 4

Installation

1. Install filter to vehicle. Install filter retaining bracket.
2. Connect filter to upper fitting. Use new fitting gaskets. Tighten upper fitting to 21 Ft. Lbs. (29 N.m).
3. Connect filter to lower fitting. Use new fitting gaskets. Tighten lower fitting to 21 Ft. Lbs. (29 N.m).

1. Clean area around injectors with carburetor cleaner and/or compressed air. Relieve fuel pressure. See FUEL SYSTEM in BASIC TESTING article. Remove PCV hose from valve cover. Remove fuel pressure regulator, vacuum hose and fuel return hose. Disconnect injector electrical connectors. Disconnect cold start valve fuel line and fuel rail inlet line.
2. Wrap a shop cloth around fuel fittings when disconnecting to collect excess fuel and place cloth in an approved container. Cover ends of components to keep dirt out and fuel in. Remove 2 fuel rail-to-cylinder head bolts. Remove fuel rail with injectors and ensure injectors DO NOT fall out of fuel Rail.

Inspection

Inspect all components for damage and replace as necessary.

To install, reverse removal procedure. Lubricate new injector "O" rings with gasoline. Tighten fuel rail-to-cylinder head bolts to 11 ft. lbs. (15 N.m). Ensure injectors rotate smoothly when mounted between cylinder head insulator bores and fuel rail. If injectors are tight and will not rotate, loosen and reinstall or fuel malfunctions will result. Tighten filter-to-fuel rail hose fitting to 21 ft. lbs. (29 N.m). Tighten fuel pressure regulator-to-fuel rail mounting bolts to 65 INCH lbs. (7.4 N.m). Tighten cold start injector fuel line to 13 ft. lbs. (18 N.m).

FUEL PUMP RELAY LOCATIONS

1. O2 sensor is mounted in exhaust manifold or in exhaust pipe just below the exhaust header. It is equipped with a permanent pigtail which must be protected from damage when the sensor is 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).

THROTTLE BODY

Note. CLEANING: Thoroughly clean parts with carburetor cleaner. DO NOT immerse diaphragms, electrical components, or synthetic parts in carburetor cleaner. Dry components with compressed air. Blow out all passages with compressed air. DO NOT use wire or pointed metal objects for cleaning. Inspect throttle body for cracks, warpage or scratches in sealing areas.

1. Disconnect negative battery cable and air intake duct. Disconnect and label all vacuum hoses, wire connectors and cable linkages from throttle body. Remove bolts retaining throttle body to intake chamber. Remove throttle body and discard gasket. DO NOT reuse old gasket. DO NOT scratch mated sealing surfaces when removing old gasket material.
2. To install, reverse removal procedure. Use new gasket for reassembly. DO NOT use sealer or glue. Tighten 4 throttle body-to-intake chamber bolts to 16 ft. lbs. (22 N.m).

THROTTLE POSITION SENSOR (TPS)

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

Removal & Installation (Prizm GSI)

With ignition off, unplug TPS harness connector and remove mounting screws. 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 ON-VEHICLE ADJUSTMENTS article.

1. With ignition off, disconnect electrical connector from throttle switch. Remove 2 screws attaching throttle switch to throttle body. Remove throttle switch.
2. To install, reverse removal procedure, ensuring flat tang of shaft is positioned into throttle switch. Rotate switch counterclockwise until it stops then turn switch clockwise to align switch slots with body holes. Install and tighten switch screws finger tight.
3. To adjust throttle switch, see THROTTLE SWITCH in ADJUSTMENTS article. Reconnect switch electrical connector.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS (PFI)