3-24 FUEL SYSTEM (EFI)
Symptoms or Possible Causes Actions (chapter)
Engine stalls easily:
Fuel pump trouble Inspect (see chapter 3).
Fuel injector trouble Inspect (see chapter 3).
Main throttle sensor trouble Inspect (see chapter 3).
Fuel pressure too low or too high Inspect (see chapter 3).
Inlet air pressure sensor trouble Inspect (see chapter 3).
Coolant temperature sensor trouble Inspect (see chapter 3).
Inlet air temperature sensor trouble Inspect (see chapter 3).
Fuel line clogged Inspect and repair (see chapter 3).
Fuel pressure too low or too high Inspect (see chapter 3).
Fuel pressure regulator trouble
Inspect fuel pressure and replace fuel pump (see
chapter 3).
Crankshaft sensor trouble Inspect (see chapter 16).
Stick coil trouble Inspect (see chapter 16).
Compression Low:
Spark plug loose Reinstall (see chapter 16).
Cylinder head not suffi ciently tightened down Tighten (see chapter 5).
No valve clearance Adjust (see chapter 2).
Cylinder, piston worn Inspect and replace (see chapter 5).
Piston ring bad (worn, weak, broken or sticking ) Inspect and replace (see chapter 5).
Piston ring/groove clearance excessive Inspect and replace (see chapter 5).
Cylinder head gasket damaged Replace (see chapter 5).
Cylinder head warped Inspect and replace (see chapter 5).
Valve guide worn or stem seal damaged Inspect and replace (see chapter 5).
Valve spring broken or weak Inspect and replace (see chapter 5).
Valve not seating properly (valve bent, worn or
carbon accumulating on seating surface)
Inspect and repair or replace (see chapter 5).
Camshaft cam worn Inspect and replace (see chapter 5).
Hesitation:
Too low fuel pressure Inspect (see chapter 3).
Clogged fuel line Inspect and repair (see chapter 3).
Cracked or obstructed inlet air pressure sensor
hose
Inspect and repair or replace (see chapter 3).
Fuel pump trouble Inspect (see chapter 3).
Fuel injector trouble Inspect (see chapter 3).
Inlet air temperature sensor trouble Inspect (see chapter 3).
Main throttle sensor trouble Inspect (see chapter 3).
Subthrottle sensor trouble Inspect (see chapter 3).
Subthrottle valve actuator trouble Inspect (see chapter 3).
Coolant temperature sensor trouble Inspect (see chapter 3).
Inlet air pressure sensor trouble Inspect (see chapter 3).
Loose injector connectors Remedy (see chapter 3).
Crankshaft position sensor trouble Inspect and repair or replace (see chapter 16).
Stick coil trouble Inspect and repair or replace (see chapter 16).
Loose terminal of battery (–) cable or engine ground
lead
Inspect and repair (see chapter 16).
Delay of ignition timing
Inspect crankshaft sensor and IC igniter in ECU (see
chapter 16).