Fuel System Diagnosis - Suzuki DF70A Service Manual

1G-13 Fuel System:
12) After checking fuel pressure, remove fuel pressure
gauge.
4
4. Joint nut

Fuel System Diagnosis

Condition
Engine will not start or
hard to start (Fuel does
not reach the fuel delivery
pipe).
Engine will not start or
hard to start.
Unstable idling / trolling
or engine tends to stall.
Insufficient engine power
in high speed range (Air
intake system failure).
Insufficient engine power
in high speed range
(Control circuit or sensor
failure).
Insufficient engine power
in high speed range
(Engine internal parts or
electrical equipment
failure).
I9J011170019-01
Possible cause
Clogging, bending or improper routing of
fuel hose.
Fuel pump failure.
Fuel pressure regulator failure.
Fuel injector(s) failure.
Wiring connection failure.
Throttle position sensor failure.
MAP sensor failure.
ECM failure.
Cylinder temp. sensor failure.
IAT sensor failure.
High pressure fuel pump failure.
Fuel hose improperly routed.
Shift position sensor failure.
Throttle position sensor failure.
IAC control system failure.
IAC passage clogged.
ECM failure.
Wire continuity / connection failure.
Fuel injector(s) clogged.
Fuel pressure regulator failure.
High pressure fuel pump failure.
Fuel filter clogged.
Clogging, bending or improper routing of
fuel hose.
Air leakage from air intake system.
Fuel pressure too low.
Throttle position sensor failure.
ECM failure.
Fuel injector(s) clogged.
Throttle position sensor failure.
ECM failure.
13) Reconnect fuel line.
14) With the engine not running and ignition switch "ON",
check the fuel system for leaks.
Correction / Reference Item
Clean, repair or replace.
Replace.
Replace.
Replace.
Repair or replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Reroute properly.
Replace.
Replace.
Check idle air control system.
Clean.
Replace.
Repair or replace.
Clean.
Check fuel pressure. Replace if necessary.
Check fuel pump and its circuit. Replace.
Clean or replace.
Clean, reroute, repair or replace.
Repair or replace.
Check fuel pressure. Repair or replace.
Replace.
Replace.
Clean.
Replace.
Replace.
Z9J0111704002