Engine Controls - Remove/install/overhaul Isuzu Amigo 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, a simple torque specification may be all that is furnished.

Removal & Installation (Except 2.3L & 2.6L)

Bring No. 1 cylinder to TDC of compression stroke and align timing marks. Disconnect negative battery cable. Remove high tension wires and distributor connector. Note direction rotor points for installation reference. Remove mounting bolt and distributor. To install, reverse removal procedure. Set ignition timing.

Removal (2.3L & 2.6L)

Disconnect battery ground cable and distributor wiring harness connector. Note and disconnect high tensions wires. Remove distributor-to-cylinder head bolt and remove distributor.

Installation (2.3L & 2.6L)

1. Remove valve cover. Bring No. 4 cylinder to TDC of compression stroke. Align camshaft pulley set mark with front plate set mark.
2. Apply engine oil to distributor o-ring. Align distributor case set mark with distributor shaft set mark. (Scheme 1) Install distributor into cylinder head.
3. Align distributor shaft set mark with cylinder head set mark. (Scheme 1) Install valve cover.
4. Install and tighten distributor-to-cylinder head bolt to specification. See «TORQUE SPECIFICATIONS»(/isuzu/amigo/i-1989-1994/remont/removal-installation/#engine-controls-removeinstalloverhaul).
5. Connect high tension wires and distributor harness connector. Set ignition timing. See appropriate SPECIFICATIONS article in ENGINE PERFORMANCE section.

Scheme 1

Disassembly & Reassembly (2.8L & 3.1L)

1. Remove distributor cap, rotor and module. Remove roll pin retaining spring. Drive out roll pin from distributor shaft. Remove drive coupling, washer, tang washer and thrust spring. (Scheme 2) Remove shaft assembly. Remove retainer, pick-up coil and pole piece from housing assembly.
2. To reassemble, reverse disassembly procedure. Check reluctor air gap. Air gap should be.008-.016" (.20-.40 mm).

Scheme 2

Scheme 3

1. Remove distributor cap, lead wire and vacuum advance. (Scheme 3) Insert screwdriver into lower side of reluctor and carefully pry it from distributor shaft.
2. File off staked end of roll pin, then drive out roll pin with a pin punch. Remove distributor shaft. Remove advance weights and springs from distributor shaft.

Reassembly

1. Attach advance springs to distributor shaft spring hanger pin. Ensure smaller tapered ends of spring (both ends) are secured to lower side of hook.
2. Align rotor shaft notches with distributor shaft notches. Install pinion gear and washers. Insert roll pin. Stake both sides of roll pin. Align scribe marks on breaker plate and distributor housing.
3. Install reluctor. Ensure reluctor roll pin notch and reluctor notch are parallel when roll pin is inserted into reluctor. Install vacuum advance unit. Apply vacuum to advance unit and ensure vacuum advance moves.

Disassembly & Reassembly (2.6L)

Remove distributor cap, rotor, packing and bushings. File off staked end of roll pin. Drive out roll pin with pin punch. To reassemble, reverse disassembly procedure. (Scheme 4)

Scheme 4

CARBURETOR

Note. For carburetor electrical component testing, see I - CARB SYS/COMP TESTS article in the ENGINE PERFORMANCE Section.

Removal & Installation

1. Remove air cleaner assembly. Remove vacuum hoses, noting hose locations for installation. Remove fuel inlet hose and accelerator cable.
2. Disconnect electrical connectors and set aside. Remove carburetor mounting nuts with Carburetor Wrench (J-26510) . To install, reverse removal procedure. Tighten carburetor mounting nuts to 12-20 ft. lbs. (16-27 N.m).

Disassembly (Major Carburetor Components)

1. Remove pump lever assist spring and pump rod split pin with washer. Remove pump lever and split pin with washer. Remove return spring, main spring and fuel-cut (slow-cut) solenoid valve. Remove fast idle cam and spring.
2. Remove choke chamber assembly and gasket. Remove air horn assembly. Remove float chamber assembly, float and gasket. Remove throttle chamber assembly. (Scheme 5) CAUTION: Disconnect fuel-cut (slow-cut) solenoid before disassembling choke chamber.
3. Remove fuel-cut (slow-cut) solenoid. DO NOT damage solenoid valve tip. Remove fast idle cam and spring. Remove choke chamber assembly.

Scheme 5

Disassembly (Choke & Float Chamber Assembly)

1. Remove vent cover. Remove mixture control (duty) solenoid (if necessary). Remove choke chamber, fuel nipple, fuel filter, fuel bowl (level gauge) cover and seal. Remove float, collar, and needle and seat.
2. Remove secondary and primary jets. Remove piston, pump cover and piston return spring. DO NOT loose check ball. Remove accelerator pump set screw, injector spring, injector weight, taper plug and slow jet spring. Remove primary and secondary slow jets. Remove main air bleeds. Remove primary slow air bleed and float chamber. (Scheme 6)

Scheme 6

Disassembly (Throttle Chamber Assembly)

1. Remove diaphragm chamber assembly, chamber cover, diaphragm spring and diaphragm. Remove idle (mixture) adjusting screw, throttle (idle speed) adjusting screw, throttle shaft nut, washer and throttle lever.
2. Remove spring hanger, shaft collar, fast idle adjusting lever and screw. Remove kick lever, return spring, return plate and sleeve. Remove adjusting lever and throttle chamber. (Scheme 7)

Scheme 7

1. Reverse disassembly procedure. Ensure all components are positioned correctly. Grease "O" rings before installing to prevent twisting and cracking.
2. If choke and/or throttle valves are removed, stake or apply adhesive compound to set screw threads to prevent loosening. Check linkage and operating levers for smooth operation.

ADJUSTMENTS

Note. Line on fuel bowl sight glass indicates proper fuel level at idle.

Float Level Adjustment

With engine running at idle, fuel level should be right on center of float chamber glass level mark. To adjust float/fuel level, remove sight glass cover and bend float seat to make necessary adjustments. (Scheme 8) Manufacturer does not supply further float level adjustment procedures.

Scheme 8

Fast Idle Opening Angle Adjustment

1. Close choke valve to fully closed position. Align fast idle adjusting screw on the first (high) step of fast idle cam. (Scheme 9)
2. Measure clearance between primary throttle valve and throttle valve chamber wall. Clearance should be.048-.058" (1.23-1.47 mm). Primary throttle valve angle should be 25 degrees. If clearance is not as specified, adjust using fast idle adjusting screw.

Scheme 9

Primary & Secondary Throttle Valve Interlock

Slowly open throttle valve until kick lever tang contacts return plate. Measure clearance between throttle valve and chamber wall. Clearance should be.27-.33" (7.0-8.4 mm). Valve angle should be 57 degrees. If reading is not as specified, adjust by bending kick lever tang. (Scheme 10)

Scheme 10

Choke Valve Opening Adjustment

Position fast idle adjusting screw tip against fast idle cam second step. (Scheme 11) Measure clearance between choke valve and choke valve chamber wall. Clearance should be.031-.051" (.80-1.30 mm). Choke valve angle should be 30 degrees. If clearance is not as specified, bend counter lever tang.

Scheme 11

Choke Unloader Adjustment

Fully open primary throttle valve. Measure clearance between choke valve and choke valve chamber wall. (Scheme 12) Clearance should be.106-.130" (2.70-3.30 mm). Choke valve angle should be 50 degrees. If clearance is not as specified, bend adjusting lever tang.

Scheme 12

O2 sensor is mounted in exhaust pipe just below exhaust header. It is equipped with a permanent pigtail which must be protected from damage when sensor is removed. Ensure sensor is free of contaminants, avoid using cleaning solvents of any type. Sensor may be difficult to remove when engine temperature is less than 120°F (48°C). Always use anti-seize compound on threads before to installation. Tighten sensor to 30 ft. lbs. (41 N.m).

FUEL SYSTEM PRESSURE RELEASE

PFI

1. Loosen fuel filler cap to relieve tank pressure. Remove fuel pump relay from underhood fuse/relay box. See «FUEL PUMP RELAY LOCATION»(/isuzu/amigo/i-1989-1994/remont/removal-installation/#engine-controls-removeinstalloverhaul) table.
2. Start engine and allow to run until it stalls. Loosen hose clamp of fuel line on side of pressure regulator coming from fuel line inlet distributor pipe. FUEL PUMP RELAY LOCATION (PFI) Model Location Amigo, Pickup & Rodeo On Right Fender Panel, Near Battery Trooper (2.6L) On Left Firewall, Near Brake Master Cylinder
3. Cover fuel hose with a shop towel and slowly pull hose from pressure regulator to relieve fuel pressure. When fuel stops leaking, reinstall hose and clamp.

TBI

Disconnect negative battery cable. Open fuel filler cap. Throttle body unit has an internal bleed feature which bleeds fuel pressure off when fuel pump is not operating.

1. Relieve fuel pressure. See «FUEL SYSTEM PRESSURE RELEASE»(/isuzu/amigo/i-1989-1994/remont/removal-installation/#engine-controls-removeinstalloverhaul__fuel-system-pressure-release) procedure. Disconnect negative battery cable. Disconnect air cleaner duct from throttle body.
2. Disconnect accelerator cable from throttle body. Remove throttle body from intake (common) chamber. Remove support bracket from fuel rail and cylinder head. (Scheme 13)
3. Remove breather hose from rear of valve cover. Disconnect pressure regulator vacuum hose. Disconnect fuel return line from fuel rail. Disconnect injector harness connector from injectors.
4. Remove fuel rail mounting bolts. Disconnect fuel supply pipe from fuel rail and lift out fuel rail with injectors. To install, reverse removal procedure. Replace injector rubber "O" rings and lubricate prior to insertion. Torque bolts to specification. See «TORQUE SPECIFICATIONS»(/isuzu/amigo/i-1989-1994/remont/removal-installation/#engine-controls-removeinstalloverhaul) at end of article.

Scheme 13

FUEL INJECTORS (TBI)

Note. The following procedure covers removing injectors without removing throttle body assembly from vehicle. For throttle body removal procedure, see THROTTLE BODY.

Removal (2.8L & 3.1L TBI)

1. Disconnect negative battery cable. Relieve fuel system pressure. See «FUEL SYSTEM PRESSURE RELEASE»(/isuzu/amigo/i-1989-1994/remont/removal-installation/#engine-controls-removeinstalloverhaul__fuel-system-pressure-release) procedure. Remove air cleaner. Disconnect connectors from fuel injectors by squeezing and pulling straight up.
2. Remove throttle body cover screws and cover, noting location of short and long screws. Remove throttle body outlet passage gasket and pressure regulator dust seal. If gasket sticks to body, leave it there. If gasket sticks to cover, remove it and place it on body. Gasket will be needed in next step.
3. With gasket on throttle body, use a screwdriver and fulcrum to carefully pry out injectors. (Scheme 15) Remove and discard "O" rings and gasket. Inspect injector filter for dirt. If dirt appears, check fuel filter, lines and tank.

Note. Replace injectors with identical part number. Injectors from other models can fit, though they may be calibrated for different flow rates.

Installation

1. Replace both "O" rings and lubricate before installing. Install injectors. Align raised lug on injector base with notch in throttle body cavity. Push down on injector until it is fully seated. Electrical terminals should be parallel with throttle shaft. 2) Install new throttle body outlet and cover gaskets. Install new pressure regulator dust seal. Install cover assembly and tighten screws to 27 INCH lbs. (3 N.m).

Scheme 14

Scheme 15

O2 sensor is mounted in exhaust pipe just below exhaust header. It is equipped with a permanent pigtail which must be protected from damage when sensor is removed. Ensure sensor is free of contaminants, avoid using cleaning solvents of any type. Sensor may be difficult to remove when engine temperature is less than 120°F (48°C). Always use anti-seize compound on threads before to installation. Tighten sensor to 30 ft. lbs. (41 N.m).

Removal & Installation (PFI)

1. Relieve fuel pressure. See «FUEL SYSTEM PRESSURE RELEASE»(/isuzu/amigo/i-1989-1994/remont/removal-installation/#engine-controls-removeinstalloverhaul__fuel-system-pressure-release) procedure. Disconnect battery negative battery cable.
2. Disconnect air cleaner duct from throttle body. Disconnect accelerator cable from throttle body. Remove throttle body from intake chamber. (Scheme 13) To install, reverse removal procedure. Tighten bolts to specification. See «TORQUE SPECIFICATIONS»(/isuzu/amigo/i-1989-1994/remont/removal-installation/#engine-controls-removeinstalloverhaul) at end of article.

Removal (TBI)

1. Disconnect negative battery cable. Relieve fuel system pressure. See «FUEL SYSTEM PRESSURE RELEASE»(/isuzu/amigo/i-1989-1994/remont/removal-installation/#engine-controls-removeinstalloverhaul__fuel-system-pressure-release) procedure. Remove air cleaner and related ducting. Remove connectors from Idle Air Control (IAC) Valve, TPS and fuel injectors. Lay wiring harness aside.
2. Remove throttle cable, return springs, transmission cable and cruise control cable, if equipped. Remove vacuum hoses, noting location for installation.
3. Remove fuel feed and return lines. Use 2 wrenches to prevent fuel nuts in throttle body from loosening. Remove and discard fuel line "O" rings. Remove throttle body mounting bolts. Remove TBI assembly and base gasket. Discard base gasket.

Install new base gasket and fuel line "O" rings. To install, reverse removal procedure. Tighten TBI mounting bolts and fuel lines to specification. See TORQUE SPECIFICATIONS at end of article.

Remove air cleaner. Disconnect TPS connector. Remove attaching screws, lock washers, retainers and TPS sensor. (Scheme 16) If necessary, remove screw holding TPS actuator lever to throttle shaft.

Scheme 16

With throttle valve in closed (idle) position, install TPS on throttle body. Ensure TPS pick-up lever is located above TPS actuator lever. Install retainers, lock washers and screws. Coat screws with thread locking compound. Connect TPS connector. Install air cleaner. For TPS adjustment, see appropriate ADJUSTMENTS article in the ENGINE PERFORMANCE Section.

Removal & Installation (Except 2.8L & 3.1L TBI)

Disconnect TPS or TVS harness connector and remove mounting screws. To install, reverse removal procedure. For TPS or TVS adjustment, see appropriate ADJUSTMENTS article in the ENGINE PERFORMANCE Section.

TORQUE SPECIFICATIONS (PFI)

TORQUE SPECIFICATIONS (TBI)

See also:
• TORQUE SPECIFICATIONS
• FUEL SYSTEM PRESSURE RELEASE