Re: CIS Fuel pressure vs EFI pressure

[Luis Marques <marques@ti.com>]

Graydon D. Stuckey wrote:
> Since I am running a fully electronic fuel system with electronic 
> injectors, the fuel pressure is not as critical as it is in the CIS 
> system.   I run a constant 3.5bar (52psig) at all times which is on
> the  high end for EFI systems.   Many run less than that.   The CIS
> changes the  pressure to vary the fuel delivery (I think.)

So, Graydon, are you programing your EFI entirely by trial and error
with the help of an oxigen sensor meter?  As I understand it, factory
EFI systems operate with a fixed fuel pressure _above_ intake manifold
pressure.  Is that what you ment?  Or do you have some kind of magical
pressure regulator that keeps the fuel at precisely 3.5bar absolute? Or
are you just leaving that port of the pressure regulator open to
atmosphere?  That could richen the mixture at higher altitudes, right?

  Luis Marques