210 likes | 343 Vues
Dive into the world of fuel injection with this comprehensive guide covering various types like TBI, CFI, and PFI, their operation, components, pressure regulation, and system checks.
E N D
FUEL INJECTION TYPES • THROTTLE BODY INJECTION (TBI) • INJECTED ABOVE THROTTLE PLATES • SINGLE INJECTOR • CENTRAL PORT INJECTION (CFI) • INJECTED ABOVE THROTTLE PLATES • USUALLY MORE THAN ONE INJECTOR • PORT FUEL INJECTION (PFI) • INJECTORS IN INTAKE RUNNERS
TBI UNIT(SOMETIMES CALLED CFI) • FIRST STEP FROM CARBURETORS • SOME CARB CHARACTERISTICS • LOW PRESSURE • MOVEABLE PINTLE • PRESSURE IS REGULATED • SERVICEABLE FIG 6-40 CLASS
LOW PRESSURE FUEL INJECTOR • 13-16 PSI • TWO O-RINGS • BALL PINTLE • USED ON TBI AND CFI SYSTEMS • MESH SCREEN • EASY TO REPLACE
PORT FUEL INJECTION • INJECTS AT EACH CYLINDER • HIGHER PRESSURE • FED OFF OF FUEL RAIL • MORE EFFICIENT OPERATION • MODES • MULTI-PORT • SEQUENTIAL
CENTRAL POINT INJECTION • GM SYSTEM • INJECTOR LOCATED IN LOWER HALF OF INTAKE MANIFOLD • POPPET VALVES • HIGH PRESSURE 60 PSI
CONTINUOUS INJECTION • SPRAYS ALL THE TIME • MIXTURE CONTROL UNIT • FUEL DISTRIBUTOR • CONTROL PRESSURE REGULATOR
FUEL PRESSURE REGULATOR • Used on TBI systems • Provides constant fuel supply • Fuel pressure on one side • Fuel pressure opens regulator under a certain pressure. • Spring is calibrated
SYSTEM CHECKS • ADEQUATE AIR SUPPLY • PRESSURIZED FUEL SUPPLY • ADEQUATE TRIGGER SIGNAL • NO VACUUM LEAKS • GOOD IGNITION SYSTEM • GOOD ENGINE MECHANICAL • GOOD FUEL QUALITY • PCM OPERATION
FUEL DELIVERY • Fuel Pump noises • Does fuel pump run at all? • Fuel filter condition? • Connections to fuel pump
COMPONENT CHECKS • AIR INDUCTION • AIR FLOW SENSORS • THROTTLE BODY • FUEL SYSTEM CHECKS • FUEL DELIVERY • INJECTOR CHECKS • INJECTOR CLEANING 6-61 LAB
INJECTOR TESTS • ELECTRICAL OPERATION • VOLTAGE SIGNALS • SCOPE TESTING • MECHANICIAL OPERATION • PINTLE OPERATION • BALANCE TEST • FLOW