[Gmecm] TBI - TPI swap ??

[bcroe at juno.com]

Actually it is possible to use the same sensor for more than 
one unit in some cases.  For example, your factory computer 
may have a temperature sensor which receives some power 
from a pullup resistor.  A Megasquirt could be attached with 
no pullup resistor, so it doesn't affect the voltage, then 
program it up for thr factory curve.  

I have a 79 Eldo with the factory Cad port injection.  The 
sensors on this are completely incompatible with later 
designs, so I just modified the (Olds small block) intake 
manifold to accept a second set of sensors.  Now with a 
new wiring harness, I can plug in about any ECU I want 
as well as the original (without opening the hood).  I have 
used 3 different types so far.  The Cad HEI even had a 
"cam sensor" output useful for sequential, though I would 
like to devise something independent of that vacuum/weight 
advance unit.  Olds has lots of bungs, but getting the 
second throttle position sensor was a little tricky.  Intake 
vacuum comes into the car, so it is just attached to the 
MAP.  Bruce Roe

21 Aug 2006  "Steve Ravet" <Steve.Ravet at arm.com> writes:
> Hi Ake, I wouldn't try to use the megasquirt and factory computer in 
> parallel, that just sounds like a wiring mess.  Both computers are 
> going to want to use lots of the same inputs, but you can't just 
> take the MAP signal and send it to both computers.  Electrically it 
> just doesn't work that way.