Fuel System info, Vortec & LS

[yossarian19]

Since I had a hard time finding the information I needed early on, I thought I'd put as much as I could in one place: this thread.

The LS-1 engines came out in 97 on the Corvette, 98 on the F-body (Camaro, Trans am) and in 99 the trucks got iron block 4.8, 5.3 & 6.0 variants.

The Corvette LS1, 97-98, used a pressure regulator on the rail & a conventional return line. In 99 and up to 04 , the Vette started using an integrated filter / regulator module that didn't reference manifold vacuum at all. It had the usual nipple-in, nipple-to-engine setup with a third nipple added that dumped pressure back to the tank over 60 psi.

The F body LS1s, 98-02, use a regulator built into the fuel sender module (integrated pump, regulator & level sender mounted in tank). These setups use a standard type fuel filter, with a T fitting shooting a line back to the regulator. Excess pressure opens the relief valve & dumps into the tank. No input from the engine influences the regulator operation. This system restricts you to the factory parts but is easy to plumb / install and is already sumped, etc with off the shelf parts.

The Vortec (truck) engines used a manifold-referencing pressure regulator on the rail & 5/16" return line from 99-03. These engines get the same 58-60 psi to the rail that all LS engines do, 3/8" feed line as usual.

In 04 the Vortecs started using a regulator that was mounted in the fuel sender, similar (I imagine) to the F body arrangements. This lasted until 2007.

Starting in 2008, Vortec engines used a separate computer to control fuel pump output, with feedback from a fuel pressure sensor. No return line - the pump only generates the pressure required for the engine.

In 2014, Corvettes will get a (new) LT1 engine with gas direct injection. 6.2 liters & 450 HP. Sweet.
TO BE ADDED: LS2 / LS3 etc fueling information.