Re: CIS Fuel pressure vs EFI pressure

["Graydon D. Stuckey" <graydon@apollo.gmi.edu>]

On Thu, 19 Jun 1997, Luis Marques wrote:

> 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

Yes, I can change the entire fuel calibration with just the change of a 
chip.   Soon, I'll be ablke to change it on the fly with my laptop.

> 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

Actually, you are right.   The back side of the diaphragm in the presure 
regulator is connected to the intake manifold, so as boost pressure 
rises, fuel pressure also rises exactly (more or less) the same amount.   
This is becasue the boost pressure is also at the outlet of the 
injectors, so you nede more fuel pressur eto maintain the expected fuel 
flow through the injector.

Later,
Graydon D. Stuckey 

"Cool name man!" - Jay Graydon   :-)