4.3L TBI

[Vandervoort, Richard D]

	Charlie

The TBI 4.3s built through 93 do not have a balance shaft, but the 94-95
does have a balance shaft.  A GM parts book can confirm this.  Fuel
Injection Specialties wants to install a stand alone harness and
controller in truck (can you say expensive kluge).  Howell did not
respond to an Email I sent asking if they can modify the 94 software to
run a CPI with a manual trans.  The same powertrain controllers were
used on the CPI and the TBI for 94.  So the powertrain controller I
currently have has the ability to run a CPI injection system, but it is
also set up to interface with an automatic transmission.  I do not know
what incompatibilities exist in CPI software when it is applied to
manual transmission, remember GM never sold this combination. 


> At 06:23 PM 5/17/98 -0700, Rich Vandervoort wrote:
> >I have a 4.3 TBI  GM v6 and would like to get more H.P. out of it as
> >cheaply as possible.  So my current plan of attack is to increase the
> >throttle body size and install a more aggressive camshaft.  Are the
> TBI
> >units for the v8 truck engines similar with larger bore sizes?  Are
> >there any camshafts that can be used with the balance shaft.  Does
> >anyone have software to monitor the ALDL signals from this motor and
> >change calibrations (94 Sonoma).  I am shying away from the CPI
> because
> >it was never used with a manual transmission. 
> 
> Rich, if you have a TBI engine, you don't have a balance shaft--it's
> only in
> the CPI engines.  Camshafts are not interchangeable between these
> engines--the TBI cam has a mechanical fuel pump eccentric but the CPI
> cam
> does not (so length is different).  You can, however, put a CPI
> manifold on
> a TBI engine and significantly improve HP.  Talk to Howell EFI
> (www.howell-efi.com) or Fuel Injection Specialties
> (www.fuelinjection.com).
> 
> Charlie Morgan
>