injection timing

[Brad Sheridan]

>How come a Bosch CIS ( continuous injection ( mechanical)) on a Porsche
>924 ( or any audi /VW for  that matter of the late 70's ) tends to have a
>MUCH smoother idle than many newer sequential efi systems. ??  The spray
>is always sprayed constantly, at the intake valve, and to mee that would
>cause puddling, and rough idle, but ironically runs smoother and better
>than most efi systems.  My car with a stock ( but soon to be modified CIS
>(K-Jetronic)) is capable of idling STEADILY at under 300 RPM. A stab at
>the gas peadle gives immmediate response. ( nearly impossible to stall it
>even at the low idle when just jabbing at the accelerator.)
>
>Anyone ever consider adding a feedback system to CIS other than
>KE-jetronic's (frequency valve ) ???  (trick is to modulate "control
>pressure", (formerly from the warm up regulator,  why not put in a
>variable valve to control pressure in the circuit to give  closed loop
>fuel delivery ?

 I think most KE-Jetronics also use the differential pressure regulator to
do what I think you're looking for. I know the one on my 16V Scirocco does.
By varying the current to the DPR, you can control the fuel delivery
electronically.
  You're getting smooth idle at 300 rpm? And good off idle response? My 8V
Scirocco with CIS had good response, most 16Vs that I've driven, or talked
to the owners of, don't seem to have nearly as good response as the 8Vs.
But I don't recall it idling down anywhere near to 300 rpm smoothly.

Brad