Re: Dual injector select on crossfire injection.

[Ludis Langens <ludis@cruzers.com>]

> Kevin Reynolds wrote:
> 
> One of the wires going into the old ECM on my 82 Camaro with crossfire
> injection is listed as dual injector select.
> In looking at the 7747 pinout it doesn't seem to want/need this wire,
> but what was it for and what function did it serve in the old ECM?

The following is speculation as I haven't played with any crossfires. 
Some crossfires use the same ECM as some single injector 4-cyl engines. 
Presumably, the hardware needs to switched between these two setups. 
Because of limp home mode, this can't be a software selected option -
the CPU might be too ill to select it.  So, that explains the dual
injector select input.  (Some later ECMs have selectable cylinder
counts.  The 1226870 and siblings can be wired for 4, 6, or 8 cylinders.)

The 1227747 doesn't have anything like this.  It's only mode is dual
injector TBI.  (Cylinder count isn't important for TBIs.)

-- 
Ludis Langens                               ludis (at) cruzers (dot) com
Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/