Veteran Ford Member
Join Date: Jan 2003
Location: Melbourne, Australia
Re: The deal with Fuel Regulators?
Alright. The fuel pump delievers fuel to the fuel rail, the injectors are mounted off this. At the end is a fuel pressure reg, it lets excess pressure out of the rail. If you mod the engine enough you'll need to get more fuel in, especially at higher revs. An aftermarket reg ups the pressure in the rail, meaning more fuel is in there for when it's needed. A rising rate regulator ups the pressure as the revs rise.
On a stock engine it's not really needed, unless it's leaning out don't bother. And yes, running an engine too lean can cause higher combustion temps and damage the engine.