two different types of manifold injection:

*the multi-point injection (MPI) system, also known as port injection, or dry manifold system
*and the single-point injection (SPI) system, also known as throttle-body injection (TBI), central fuel injection (CFI), electronic gasoline injection (EGI), and wet manifold systemIn this article, the terms multi-point injection (MPI), and single-point injection (SPI) are used. In an MPI system, there is one fuel injector per cylinder, installed very close to the intake valve(s).