LT1 EFI Question

[Eric Elliott]

Neat solution. Change the MAP output measured, the fuel feed changes to
compensate, it works. Even if my information is wrong, your solution would
probably work for most EGR checks.
Besides I just assumed the Ford 5.4 Triton uses the EGR flow for its EGR
test. It may measure EGR flow but test EGR by an older method.

Eric
-----Original Message-----
From: Bruce Plecan <nacelp at bright.net>
To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
Date: Friday, April 03, 1998 10:59 AM
Subject: Re: LT1 EFI Question


>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......
>