Hard Starting

SYMPTOM DESCRIPTION:

Engine cranks OK, but does not start immediately. Will eventually start and run, but may die shortly after.



SYSTEM OR COMPONENT TO CHECK ACTION

COMPUTER INPUTS/OUTPUTS CHECK: - COOLANT TEMPERATURE SENSOR (CTS):
Using a "Scan" tool compare coolant temperature
with ambient temperature on a cold engine.
If coolant temperature reading is 5 degrees
more than or less than ambient air temperature
on a cold engine, check for high resistance in
coolant sensor circuit or sensor itself.
- THROTTLE POSITION SENSOR (TPS):
If a sticking throttle shaft or binding linkage
causes a high TPS voltage (open throttle
indication), the ECU will not control idle.
Monitoring TPS voltage, a "Scan" tool and/or
voltmeter should read less than 1.25 volts
with throttle closed.
- IDLE SPEED MOTOR.
- NO CRANK SIGNAL.





FUEL CHECK: - FUEL PRESSURE
- WATER CONTAMINATED FUEL
- FAULTY IN-TANK FUEL PUMP CHECK VALVE:
This could allow the fuel in the lines to drain
back to the tank after the engine is stopped.
To check for this condition:
1. Ignition "OFF."
2. Disconnect fuel line at the filter.
3. Remove the tank filler cap.
4. Connect a radiator test pump to the fuel line
and apply 103 kPa (15 psi) pressure.
If the pressure will hold for 60 seconds,
the check valve is OK.










IGNITION CHECK: - Proper ignition voltage output with
appropriate spark tester.
- Spark plugs, wet plugs, cracks, wear,
improper gap, burned electrodes or
heavy deposits.
- Bare and shorted wires.
- Moisture in distributor cap.
- Worn distributor shaft.
- Pickup coil connections.
NOTE: If engine starts, then immediately stalls,
disconnect the set timing connector. If engine
then starts, and runs OK, replace distributor
pickup coil.





EMISSIONS CHECK: - EGR SYSTEM: Valve operation.
NOTE: Refer to EMISSION CONTROLS for testing procedures.