[Marc Haibeck]

Hi Jim,

For the LT5 the fuel pressure should be 43 psi +/- 1 psi at idle for and engine with normal manifold vacuum.

I think that the best way to diagnose fuel delivery is to observe the pressure at WOT. Attach a fuel pressure gauge to the windshield and recruit a co-pilot. Run the car at WOT from 3000 to 7000 rpm. The fuel pressure should snap from 43 to 51 psi +/- 1 psi.

If the fuel pressure drops to 47 psi or less you may observe reduced power, knocking and a lean fuel code if it persists for two seconds.

A common situation is a failed fuel pump. At WOT on a single pump the fuel pressure will be 51 psi until about 5500 rpm and then the pressure will sag to about 45 psi at peak power.

Best of luck.

Marc