Hi all,

Ive just been doing some reading up on fuel injection methods n i had a quick question about the MPI engines in the felicia's n early fabia's.

As far as i can understand Single Point Injection is where the fuel is sprayed directly after the throttle body, acting as a carburettor.

However Multi Point Injecition is what is confusing me, now is it that each cylinder has fuel directly injected into the combustion chamber, or is it that the fuel is injected into the intake manifold before each set of intake valves, therefore having multiple points of injection in the one manifold.

Some internet sources are saying MPI is injection before the valves, and others are saying its direct into the cylinder. Are both right or am i getting the wrong end of the stick?

I Also watched a VW promotional video about the 1.2 TSI engine, now that advertises a direct injection system, but i have also heard that same system called MPI.

Thanks

T

You are right in both instences altho mpi is usually injectors before inlet valves and direct injection is straight into cuylinder like modern diesels do

Ok so the modern engines like the 1.2 TSI might use Direct Injection, but an engine like the 1.4 MPI in the early fabia's (like engine AQW) might inject before the valves?

Some modern engines (e.g. 3rd generation 1.8TSI) have two sets of injectors and employ both MPI and direct injection simultaneously.

link

Edited 20 August, 201213 yr by briskycat