Re: TPI '165 pulling timing after Cold start

[Ludis Langens <ludis@cruzers.com>]

"Marteney, Steven J." wrote:
> 
> Any idea how it works?  Simple RC time constant?  Or is it hidden in a
> "limp-home" chip somewhere?
> 
> > Anyone know if the 165 ECM controls the 2 second fuel pump enable when no
> > oil pressure is present?  where that may be in the code?

In the C3's, this is hidden in the limp home chip.  There obviously must
be a digital counter that times the 2 (or whatever) seconds.  It might
be controlled by a RC oscillator.

In the P4's, is is hidden in the chip that interfaces to the EST module
and handles the P&H injector function.  This chip has an RC oscillator
that controls many of it's functions.  The fuel pump output must be
controlled by a digital timer clocked by the RC clock.

-- 
Ludis Langens                               ludis (at) cruzers (dot) com
Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/
----------------------------------------------------------------------------
To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
in the body of a message (not the subject) to majordomo@lists.diy-efi.org