does anyone know this just so i can measure? my car was running 25-30 and idling really rough so i brought it up to 40 with an aftermarket regulator and its smoother but i cant bring the idle down (another thread about this)

 

OK.

Engine running and vac to the stock reg (yeh I know you got something else, I will get to that in a minute) is ABOUT 31psi.

Engine OFF, and rail primed is ABOUT 40psi.

Mine runs a PreHE reg, and I have set it at 29.5psi and MY engine is sweet.

If I "play" with the adjusting screw VERY carefully I can get the engine to run crap within about a 1psi movement from that setting. It is just like a mixture screw on a carby (for those who remember carbies????).

Another here runs sweet at 30.5psi, and as everyone knows, NO 2 ENGINES ARE THE SAME.

I would back that pressure OFF to 30 psi, warm it up properly and the turn the pressure screw VERY slowly, and see what YOUR engine likes. It will NOT be anywhere near 40psi trust me.

Once that is sorted, set the idle speed.

 

someone else told me 40 psi was teh correct pressure, but i had it at 30 and the engine was running crazy rough and wouldnt free rev above 4000 but then i moved it to 40 and its so smooth and revs to 6g without even trying. idk when it gets out of the body shop ill hook up the couble o2 gauges i got and see how its running