88h & hi-way stuff

[Kevin R]

I know I asked this before, but any chance the 7747 has a hiway fuel to go
along with the hiway spark?

Kevin R

>
> Here is the info to enable & setup the hi-way spark and fuel
> on a mask 88h bin. This mask is used on the '730 powered
> 3.1L f-bodys', along with a myriad of fwd 3.1 & 3.4l stuff.
>
> The way it works is that hi-way spark needs to be present
> before hi-way fuel is considered. The user option word at
> prom address 0x6B8 has two qualification bits. They are:
>
> 10h    if set, tcc needs to be locked for hi-way spark
> 02h    if set, must be in high gear for hi-way spark
>
> After that, the following are checked:
> ;
> ; --------------------------------------
> ; HiWay spark quals
> ; --------------------------------------
> ;
>
> 0x8088 224 ; max map, 90Kpa (Kpa = N * 0.3125 + 20)
> 0x8089 147 ; min coolant (70.25øC)
> 0x808A 48 ; min rpm (1200)
> 0x808B 2 ; timer, sec's
> 0x808C 0 ; timer, sec's
>
> The next table defines how much spark is added:
>
> 0x808E  ; HiWay SA table vs. map
>
> 20    0
> 25    0
> 30    0
> 35    0
> 40    0
> 45    0
> 50    0
> 55    0
> 60    0
>
> Hi-way spark values of 0 disable the hi-way fuel. So, set to a
> minimum at 1/3 degree of spark.
>
> The option bit at: 0x6B9, 80h, set to a 1 enables hi-way fuel.
>
> Once hi-way spark becomes active, hi-way quals are tested. They
> are nothing more than the vehicle speed.
>
> ; 0x872B 48, 50  ; hi-way fuel: mph thresholds, w/hyst
>
> If they pass, the commanded afr becomes:
>
> ; 0x872D 154  ; hi-way fuel: afr * 10
>
>
> Have fun,
>
> BobR.
>


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