gjw@floyd.UUCP (04/30/84)
I would like to make a clarification to an article on the 85 Corvette fuel injection system. The article stated that the port fuel injection system injected fuel directly into the cylinders. WRONG! The port type fuel injection system has seperate injectors for each cylinder unlike the Vette's current Throttle Body Injection (TBI) which has only two injectors each located upstream of a throttle plate. The port type system has each injector located in front of the intake valve for each cylinder and does not inject the fuel directly into the cylinders. The last gasoline powered street engine that injected the fuel directly into the cylinders was the Mercedes 300SL Gullwings of the late 50's. The port type system is the preferred fuel injection system used on most higher performance cars since the metering of fuel is more accurate than the TBI system. In the port type system the fuel is injected usually but NOT ALWAYS! when the intake valve is open. In the TBI system the fuel and air mixture must pass the throttle plate, go through the intake manifold then through the intake valves. All the drawbacks of fuel-air mixing distribution and precipitation common in carburetor setups is present. In the 85 Corvette the power output was increased by almost 20% due to the more accurate metering possible with the port fuel injection and still meet emission levels.