Electronic Ignition System Diagnosis; Evap Canister Purge Solenoid; Visual Check Of The Evaporative Emission Canister; Idle Air Control (Iac) Valve - Isuzu 1999 RODEO Workshop Manual

ELECTRONIC IGNITION SYSTEM
DIAGNOSIS
If the engine cranks but will not run or immediately stalls,
the Engine Cranks But Will Not Start chart must be used
to determine if the failure is in the ignition system or the
fuel system. If DTC P0300, P0341, P0342, or P0336 is
set, the appropriate diagnostic trouble code chart must be
used for diagnosis.
If a misfire is being experienced with no DTC set, for
diagnosis, refer to the Symptoms section.

EVAP CANISTER PURGE SOLENOID

A continuous purge condition with no purge commanded
by the PCM will set a DTC P1441. A fault (small leak) in
the EVAP purge vacuum system will set a DTC P0442.
Refer to the DTC charts for further information.
VISUAL CHECK OF THE
EVAPORATIVE EMISSION CANISTER
f If the canister is cracked or damaged, replace the
canister.
f If fuel is leaking from the canister, replace the canister
and check hoses and hose routing.
RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION
014RX001

IDLE AIR CONTROL (IAC) VALVE

The Tech 2 displays the IAC pintle position in counts. A
count of "0" indicates the PCM is commanding the IAC
pintle to be driven all the way into a fully–seated position.
This is usually caused by a vacuum leak.
The higher the number of counts, the more air is being
commanded to bypass the throttle blade. In order to
diagnose the IAC system, refer to IAC System Check.
For other possible causes of idle problems, refer to
Rough, Unstable, or Incorrect Idle, Stalling in Symptoms.

FUEL SYSTEM PRESSURE TEST

A fuel system pressure test is part of several of the
diagnostic charts and symptom checks. To perform this
test, refer to Fuel System Diagnosis.

FUEL METERING SYSTEM CHECK

Some failures of the fuel metering system will result in an
"Engine Cranks But Will Not Run" symptom. If this
condition exists, refer to the Cranks But Will Not Run
chart. This chart will determine if the problem is caused by
the ignition system, the PCM, or the fuel pump electrical
circuit.
For the fuel system wiring schematic, refer to Fuel
System Electrical Test.
If there is a fuel delivery problem, to diagnose the fuel
injectors, the fuel pressure regulator, and the fuel
pump,refer to Fuel System Diagnosis.
If a malfunction occurs in the fuel metering system, it
usually results in either a rich HO2S signal or a lean HO2S
signal. This condition is indicated by the HO2S voltage,
which causes the PCM to change the fuel calculation (fuel
injector pulse width) based on the HO2S reading.
Changes made to the fuel calculation will be indicated by
a change in the long term fuel trim values which can be
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