After three weeks (yes I know, but everything takes longer now that I'm
getting married :-}) I finished installing the fuel injection on the V6.
The verdict - MUCH better throttle response from part to about 3/4 range,
no more idle drop when I turn on the H4 head lamps, or when the two cooling
fans for the radiator come on from the alternator drain. Much improved
idle mixture as noted from not getting watery eyes when standing too close
to the exhaust while idling as before (I know :-} but it's happened on rare
occasion and not in an enclosed space however as I don't idle the car in
the garage for extended periods). No more rich smell from the exhaust and
improved fuel mileage, pretty much as I suspected. Not that the Weber was
that far out of calibration, but the system now has a better handle on
mixture control and has the capability to make adjustments to the mixture
in real time that was just not possible before. It's really cool to see
the fuel exiting in a fine conical mist from the two injectors at idle, and
then turn to a heavy conical spray when I blip the throttle! The downside.
. .Full throttle is not correct, it appears to be running severely lean,
with the motor reacting as if it's running on three of the six cylinders.
I am not sure if this a temporary condition, in which the GM computer has
to "learn" this engine, system combination (I doubt it), or a calibration
condition (which would have to be burned into the chip by someone else). I
don't think it's a fuel pressure problem (although I haven't verified this
as of yet) because I installed a new fuel pump, 3/8ths dia pressure, and
return fuel lines, and a large injection type filter. I did install the
filter before the pump, between the pump and the tank but I don't feel this
is a problem because the tank fitting is directly in the bottom of the tank
and as such is a gravity feed (requiring no priming to start flow). It
does appear as if there isn't enough fuel at full throttle conditions
though, and I'll have to see what I can find out. Unfortunately, this is a
GM computer, and the *fuel maps* are not adjustable via laptop as are some
of the more complex systems out there. I am just having so much fun
driving around I haven't bothered to trouble shoot yet! I have written to
Howell-EFI (which is who calibrated the GM chip for my system) to see what
they advise-but for now I'll just have to keep my foot out of it!
Barry Schwartz (San Diego) bschwart@pacbell.net
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