throttle body vs multiport
scrap_iron
02-10-2005, 04:52 AM
Can anyone tell me what are the advantages/dissadvantages of multiport fuel injection vs throttlebody designs ?
JDPascal
02-11-2005, 02:04 AM
While the throttle body FI has precise metering, there is still a possibility that some cylinders could run rich or lean depending on manifold runner design.
With the multiport, the fuel is injected into the manifold runner right before the air enters the intake port in the cylinder head and fuel mixtures can be more consistant.
If you have an injector fail with the throttle body type, you loose several cylinders. one injector failing in a MPI system is not so serious to starting and running. Not that you would want to do it but the engine likely would limp along.
JD
With the multiport, the fuel is injected into the manifold runner right before the air enters the intake port in the cylinder head and fuel mixtures can be more consistant.
If you have an injector fail with the throttle body type, you loose several cylinders. one injector failing in a MPI system is not so serious to starting and running. Not that you would want to do it but the engine likely would limp along.
JD
scrap_iron
02-11-2005, 04:32 AM
I have an 88 with the Multiport, but I see throttle body was used on later Cherokees - Thanks !
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