Vortec fuel injection is Chevrolet’s trade name for Multi-port fuel injection. Lot of cars use this system.

The reason I want to Identify the particular style of fuel injection Chevy uses is that there are several versions of fuel injection used today on automotive engines. From purchasing a rebuilt engine to simply buying replacement parts, knowledge is power. Don’t get the wrong parts.

Multi-port fuel injection (MPFI) injects fuel into the intake port just upstream of the cylinder’s intake valve, rather than at a central point within an intake manifold, referred to as (SPFI), or single port fuel injection. MPFI systems can be sequential, in which injection is timed to coincide with each cylinder’s intake stroke, by the ECM, in which fuel is injected to the cylinders in groups, without precise synchronization to any particular cylinder’s intake stroke, or Simultaneous, in which fuel is injected at the same time to all the cylinders.

All modern EFI systems utilize a form of sequential MPFI. Briefly, I want to note that the throttle bores on the actual maniflod wear and cause a vacuum leak at that point, which necessitates manifold replacement. The maniflod needs to be tested carefully before it is reinstalled on a rebuilt engine. It won’t cause a failure, but it will cause a rough idle and a brief stumble on takeoff. Simple to say you will lose some performance and gas mileage too.

This is one of the most efficient fuel injection setups made..What ever you call it. Vortec or Sequential MPFI. Essentially it is now in the same ball park as direct port fuel injection systems. It should be obvious this is a computerized system, therefore making it a relatively modern setup. Although some Toyotas and other Japanese cars from the 1970s to the early 1990s used an application of Bosch’s multipoint L-Jetronic system.

Essentially we have an intake manifold that has an injector placed in the manifold over the appropriate intake port and valve in the head. Obviously there is an air filter on the top of the intake manifold to filter the air entering the engine. Meaning, unlike throttle body fuel injection or a carburetor, both of which sit on the top of the intake manifold, the distribution of fuel coming from the top. The Vortec style has an injector for each cylinder.

The performance and fuel efficiency boost along with lower emissions, hence carbon footprint, provide an affordable to manufacture system that outperforms other forms of fuel injection in almost all ways.

I will be covering TBI and Direct Port injection next. GotEngines.com blog will continue with the different types of fuel injection setups in future posts, stay tuned and enjoy..