Two TBI units, one ECM

[Walter Sherwin]

Ummmm..............the "749"  houses two 4/1 Amp peak&hold injector current
drivers, which were originally intended to drive two individual parallel
sets of 2/.5 Amp peak&hold Rochester port injectors.  This particular box
was expected to drive the the two pairs of injectors in either SSSF or SSDF
port fuel mode.  Both electrically, and programatically, this is entirely
different than what is required for dual channel TBI control, especially if
you want to run "twin" TBI's.

For "twin" TBI's, your best bet is to procure a TBI box, and add an external
2-input to 4-output 4/1 Amp peak&hold injector driver box.  All of the other
electrical and programatic options are serious compromises, no matter the
cost savings.  Remember, each TBI injector expects to see 4/1 Amps for
proper operation and control.


Walt.





>That might work, but I haven't tried it,
>would also take building a calibration from scratch if it did.
>Maybe copy something like AUJP into the values for the 749 but geez, that
>seems like a lot of work..
>Again it's one of those things that "might" work, but I don't know anyone
>that's tried it
>(Sounds like another job for Doc+Sneezy)
>Grumpy
>
>
>>If that is a problem, you could just set the MAP
>>selection bit to one bar and use one bar MAP. (?)
>>Mike V
>>
>>> Driver wise it could,
>>>  But, it uses a 2 bar MAP so you lose resolution.  On high HP N/A I
wouldn't
>>>  even try.
>>>  Could use 730 code as I have mentioned before.  But have to watch the
>>gotcha'
>>> s
>>>  Injector firing differences pop up again.  I've run 730 code in a 749
at
>>>  about 300HP, but 400 is a big step.
>>>  Some one with alot of talent, and software experience on thing, new
guy,
>>>  kinda a strech.
>>>  Grumpy
>>>
>>>  >I wanted to expand on this the other night,
>>>  >but didn't have time...
>>>  >Why can't the 7749 run two 454 (two barrel) TBI units?
>>>  >As used in the Turbo Sunbird, it has two drivers that
>>>  >fire two P&H injectors each...
>>>  >Inquiring CSH wearers wanna know
>>>  >Mike V
>>