Engine Controls - Remove/install/overhaul Isuzu Impulse II

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 (1.6L Turbo)

Remove intercooler. Remove ignition coil cover. Disconnect wiring connectors and spark plug wires. Remove DIS assembly. Ignition coils may be removed separately. To install, reverse removal procedure.

Note. DIS ignition coils are identical and interchangeable.

Removal & Installation

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.

Disassembly & Reassembly

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 1) 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 1

FUEL SYSTEM PRESSURE RELEASE

Note. Fuel pump relay is located on left fender panel, behind battery.

1. Loosen fuel filler cap to relieve tank pressure. Remove fuel pump relay from underhood fuse/relay box.
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.
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.

Removal & Installation (Except Turbo)

1. Relieve fuel pressure. See 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 2)
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 table at end of this article.

Scheme 2

Removal & Installation (Turbo)

1. Relieve fuel pressure. See FUEL SYSTEM PRESSURE RELEASE procedure. Disconnect negative battery cable. Drain engine coolant.
2. Remove intercooler cover and intercooler. Remove air cleaner duct and upper case. Disconnect accelerator cable from throttle body. Remove backpressure transducer and VSV vacuum pipe. Remove intercooler upper bracket. Remove throttle body from intake (common) chamber.
3. Remove EGR valve. Disconnect fuel pressure regulator vacuum hose and fuel return pipe from pressure regulator. Disconnect injector harness connectors from injectors. Disconnect fuel feed pipe from fuel rail. Remove fuel rail with injectors.
4. To install, reverse removal procedure. Replace injector rubber "O" rings and lubricate prior to insertion. Torque bolts to specification. See TORQUE SPECIFICATIONS at end of this article.

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).

1. Relieve fuel pressure. See 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 2) To install, reverse removal procedure. Tighten bolts to specification. See TORQUE SPECIFICATIONS table at end of this article.

THROTTLE POSITION SENSOR (TPS)

Disconnect TPS harness connector and remove mounting screws. TPS is an auto-zeroing type and is not adjustable.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS (PFI)