no, it filters junk out of the fuel, like dirt n' shit. that’s all it does. When it gets clogged, the flow rate is reduced. The engine running rich due to a lower pressure (pressure in the line after the filter, because it's flow rate is reduced from being clogged) does not make a whole lot of sense to me and someone would have to explain that. Either way, the "richness" is attributed to the air:fuel ratio. Rich means there's more fuel than air than the stoichiometric optimum that the computer calculated. Lean means there’s more air than fuel from the calculated optimum.
The ratio at sea level is something close to 1:10 (fuel:air)... I think. I could be totally wrong with that figure, and it doesn’t matter for the purposes of this explanation, but that's just an example. The computer calculates rpm, mass of air (which varries according to density due to pressure & temperature, recorded at the MAF) and a couple of other variables like throttle to determine the correct ratio of fuel to inject. If the fuel pressure isn't right, injectors get clogged, etc etc, the system gets fucked up and thus you loose power.
The fuel filter's gotta be really slogged to really start affecting power.
Last edited by bitcore; 11-10-2005 at 11:38 PM.