Electromotive TEC-II?

Mazda Ebrahimi kleenair at ix.netcom.com
Wed Nov 20 23:57:19 GMT 1996


David Gould wrote:
> 
> > Regarding idle control and canister purge, a good option is to leave the factory
> > electronics intact, and let the factory system control these functions, while you use a
> > simple aftermarket system like electromotive to control the fuel.  The only problem is
> > that the "check engine" light will come on.  If this was a domestic car, I could sell
> > you all the "fixes" you need to prevent the light from comming on.  But since it's an
> > import, you may have to put up with it, and clear codes and reconnect the factory system
> > before your inspection!
> 
> Do you mean basically to wire it up like this:
> 
> Stock ECU
> 
>  Inputs: water temp, tps, crank pos, egr valve pos  NORMAL
>          MAF, air temp DISCONNECT
> 
>  Outputs: radiator fan, ISC valve, egr, canister purge  NORMAL
>           ignition, injectors, fuel pump relay DISCONNECT
> 
> Electromotive:
> 
>  Inputs: water temp, IAT, MAP, crank pos, tps
>  Outputs: ignition, injectors, fuel pump relay
> 
> So that basically the stock ecu runs the cooling fan, EGR, cannister, and idle
> speed while the new ecu runs the timeing and fuel.
> 
> Clever idea, anyone ever do this?
> 
> -dgWe have over 700 vehicles running on a secondary fuel injection system using this 
method.  The only problem you are going to have is the check engine light, and there are 
ways around that if you are clever about it.  Here are some common tricks:
-Send a fake O2 signal to the factory ECU to make it happy,
-Simulate OEM injector resistances with a resistor bank, so its happy,
-Send a fake temp on the coolant sensor to freeze adaptive learn if that is a problem
-Or if everyting else fails, send a clear code signal to the ECU every once in while.  I 
have access to such a box for Ford and GM OBD-II computers.

If you are making major intake and exhaust modifications you probably wouldn't want to 
do this, but you could also relay your injectors, so you can flick a switch and go back 
to the factory fuel curve on the fly!



More information about the Diy_efi mailing list