LT1 EFI Question

[Bruce Plecan]

From: Eric Elliott <eelliott at arkansas.net>
Subject: Re: LT1 EFI Question


>Hello,
>The old GMC pickup had a 1988 TBI EFI system, 1227747, PROM "AMUR".
>The new Ford has a PCM that I have found no information on except what is
in
>the Electrical & Vacuum Manual.
>>>Hello,
>>>Older GMC ECMs diddled the EGR & looked at injector duration to se if EGR
>>>functioned. So it had to actually change AFR via EGR to pass test. Test
was done after engine warm.My new 5.4 L measures
EGR flow with a differential pressure transmitter.
>>>Another case where a resistor won't fool it.
>>>Eric
>>
>>And perchance what ecm would be an example of that?..
>>Bruce
>
Kinda funny in a way, what I did on a EGR Coding TBI was use the
EGR lead wire to trigger a voltage divider (resistor bridge) on the MAP
signal to stop the coding.  I thought the ECM was looking for a MAP signal
change to see if it was working, never thought it was looking for a injector
pulse change.  It did get rid of the coding thou.
Bruce    I'm sure glad my Cone Shaped Hat covers the bruises
              from beating my head against the wall......