Who can really tune?

[Jetblack]

I'm new to fuel pressure. I know stock pressure for a 2g is 43 psi with hose off. I have a Wb 255hp with 660 injectors, afpr w/gauge set for 43. How do I know if I should raise fuel pressure above or below 43psi? My idle is high around 1200-1500 rpms would like it to be lower. MAFT set @ 0 across the board because I have DSM link for 660's. Any suggestions?

 

[LandoAWD]

Why not just set your BISS screw to lower the idle?

 

[kpt4321]

Laando is right. Before you do anything else, fix your idle. I bet it's not just the BISS, but it could be. Figure that out.

There is no little blinking light that will tell you to raise your fuel pressure. 43 psi is a good starting point, and I can't really tell you certain cases where you want to raise it. There are scenarios where it's a choice, like when you need more fuel or you want to make changes to the A/F ratio without effecting timing as much.

 

[Jetblack]

The thing is my BISS is all the way in.

 

[kpt4321]

You have post throttle body vacuum leaks. Time for a pressure test.

 

[Jetblack]

You're probably correct. I recently fixed one at the throttle body gasket and found another leak aT THE INTAKE MANIFOLD. I replaced the gasket but I didn't clean off the mating surfaces so it's possibly still leaking. I'll just have to redo it and chaulk it up as a learning experience to clean the surfaces good.

 

[kpt4321]

Build a real pressure tester, if you have not already.

 

[doug]

Originally posted by Jetblack
The thing is my BISS is all the way in.

Remember that you can't just screw it in on a 2G. Since you have DSMLink, you need to hit the button that says "GND Diag" in the Miscellaneous dialog box before adjusting the BISS. Someone correct me if that's not right, but it's the way I understand it from the DSMLink User's Manual and the forums.