RE return to fuel tank

[Espen Hilde]

Many good points here!

----------
> From: Greg Hermann <bearbvd at sni.net>
> To: diy_efi at efi332.eng.ohio-state.edu
> Subject: Re: RE return to fuel tank
> Date: 23. oktober 1998 00:10
> 

> The most stable fuel pressure control will be possible if you use a
> variable drive fuel pump,  a pressure regulator,  feedback on what the
> regulator is doing from a fuel pressure transducer, and a controlled
> reference pressure on the back side of the fuel pressure regulator
> diaphram, as well as a fuel temperature transducer to allow proper
> correction for fuel density. Use the fuel pressure regulator as the
primary
> control with control over pump speed following what is going on so as to
> minimize the amount that the regulator armature has to move in order to
> keep the fuel pressure where the computer wants it. This also allows you
to
> vary fuel pressure to wherever you want it at different points on the
> engine MAP/speed matrix so as to maximize the dynamic range of the
> injectors.
 
> With proper PID control over what the regulator and pump are doing, one
> could get extremely stable, but variable fuel pressure control, and thus
> much closer f/a ratio control over a wider dynamic range. Yes, there is
> room here for a code guy to figure out how to put some learning blocks
into
> this loop so that the control loop could anticipate things a bit, and
hold
> things even closer.
> 
> Also, with the fuel pressure transducer input, the computer could catch
any
> pressure glitches on the fly, and correct pulse widths accordingly.
> Injector pulse widths could also be corrected for fuel temperature in the
> rails on the fly.
This is the way to go.....
How fast does a common pressure regulator react? I dont know , but I
suspect it slows the efi systems
reactiontime to sudden changes . I think the weak link in the Efi system is
the acclerations enrichments ,
and the rather crude covering up of a slow reacting system.A realy fast car
Is not finished consuming its
enrichments before its time to change gear, and put a new round of
enrichments in again.
I wonder if a calculation done from one trottle position to another ,during
one cyl. intake stroke would perfom better in a fast car.(Take a average of
trottle possition during one intake stroke and us it insted of map or maf
at sudden trottle reaction).
Why is not engine temperature controlled by ecu? Warm engine for light
cruise ,cold for wot.Warmer engine at cold outside temp.....
Thinking loud again.....
Espen Hilde