scan tools and WOT

[Terry]

Andrew F. Gunnesch wrote:
> 
> That's interesting...  my TPI car, when the Diacom puts it into ALDL mode
> (I haven't been able to get it to link in diagnostic mode) everything works
> just fine.  I can watch the timing being varied too.  It drives normally.
> 
> Maybe that's because this is a TPI ECM?


I made an interesting observation while at the track this past Saturday.
I made 4-5 runs with Diacom recording data.  Then I made 5-6 runs with
the Diacom disconnected.  Guess what?  I was both quicker and faster
by .1-.15sec and 1mph with the Diacom disconnected....

Wonder why????  This is on any '87 TPI/MAF motor.  Is the ECM that slow
that it can't optimally control the motor at WOT while transmitting
data?

thanks,

T.