Fuel System Service Information - Honda GL1800 Service Manual

SERVICE INFORMATION
GENERAL
• Work in a well ventilated area. Smoking or allowing flames or sparks in the work area or where gasoline is stored can
cause a fire or explosion.
• Be sure to relieve the fuel pressure with the ignition switch turned to "OFF."
• Bending or twisting the control cables will impair smooth operation and could cause the cables to stick or bind,
resulting in loss of vehicle control.
• Do not apply commercially available carburetor cleaners to the inside of the throttle bore, which is coated with
molybdenum.
• Do not snap the throttle valve from full open to full close after the throttle cable has been removed. It may cause
incorrect idle operation.
• Seal the intake manifold ports with tape or a clean cloth to keep dirt and debris from entering the engine after the
throttle body has been removed.
• Do not damage the throttle body. It may cause incorrect throttle and idle valve synchronization.
• Prevent dirt and debris from entering the air passages after the throttle body has been removed. Clean them using
compressed air if necessary.
• The throttle body is factory pre-set. Do not disassemble in a way other than shown in this manual.
• Do not loosen or tighten the white painted bolts, nuts and screws of the throttle body. Loosening or tightening them can
cause throttle and idle valve synchronization failure.
• Tighten the yellow painted bolts of the fuel rails to the specified torque.
• The parts of the throttle body not shown in this manual should not be disassembled.
• Always replace the O-ring when the fuel pump is removed.
• The PGM-FI (Programmed Fuel Injection) system is equipped with the self-diagnostic system described on page 5-8.
• When checking the PGM-FI system, always follow the steps in the troubleshooting flow chart (pages 5-16 through 5-55).
• The PGM-FI system is provided with a fail-safe function to secure a minimum running capability even when there is
trouble in the system. When any abnormality is detected by the self-diagnosis function, running capability is
maintained by preset value in the simulated program map. When any abnormality is detected in the injector(s), ignition
pulse generator and/or camshaft position sensor, the fail-safe function stops the engine to protect it from damage.
• A faulty PGM-FI system is often related to poorly connected or corroded connections. Check those connections before
proceeding.
• When disassembling the fuel system parts, note the location of the O-rings. Replace them with new ones upon
reassembly.
• Always replace the sealing washer when the sealing bolt in the fuel rail is removed or loosened.
• Use a digital tester for PGM-FI system inspection.
• See section 17 for FI IGN relay inspection.
• See section 19 for the following components:
– ECT sensor
– fuel level sensor
– gear position switch
SPECIFICATIONS
Throttle body identification number
Throttle grip free play
Intake air temperature sensor resistance (20° C/68° F)
Engine coolant temperature sensor resistance
(20° C/68° F)
Throttle position sensor resistance (20° C/68° F)
Fuel injector resistance (20° C/68° F)
Camshaft position sensor peak voltage
Ignition pulse generator peak voltage
Manifold absolute pressure at idle
Fuel pressure at idle
Fuel pump flow (at 12 V)
Idle speed
ITEM
FUEL SYSTEM (Programmed Fuel Injection)
SPECIFICATIONS
GQ61A
2 – 6 mm (1/12 – 1/4)
2.2 – 2.7 kΩ
2.3 – 2.6 kΩ
4 – 6 kΩ
11.1 – 12.3 Ω
0.7 V minimum
0.7 V minimum
400 – 450 mm Hg (15.7 – 17.7 in Hg)
2
343 kPa (3.5 kgf/cm , 50 psi)
3
133 cm (4.5 US oz, 4.7 Imp oz) minimum/10 seconds
700 ± 70 rpm
5-3