Injector Impedance how low can i go...

[Richard Wakeling]

Hi Stuart,
	I recently discovered that the "808" seems to have the ability to drive
a couple of low impedence injectors in peek and hold mode. 	There is
provision already on the PCB to use the existing saturation injector
driver in peek and hold mode by,

	   1) Disconnecting the wire D10 at the ECU. This is the injector
driver's ground circuit (source) which goes to engine ground.

           2) Put jumper wire between D9 and D10 on ECU, this will put a
0.1 ohm resistor which is already on the PCB in series with the injector
drivers source and ground. This 0.1 ohm resistor is used to sense
current for Peek & hold.
 
	I have not tried this wiring modification myself and I would suggest
that a check should be made to see if the injector driver controller
used and  driver mosfets used in the "808" are the same as in the "749"
which has two injector drivers when used for the Sunbird's four low
impedence injectors.

Cheers Richard.
 
Stuart Bunning wrote:
> 
> I am using a GM 1227808 Aussie ECU.
> I want to know what impedance injectors it can drive.
> on a V8 we have 8 16ohm injectors in parallel about 2 Ohmn load.
> 
> I want to play with a TBI that has 2 injectors which are about 1.8 Ohm each
> so if i parallel then up the ecu will see about .9 Ohm.  Will this melt the
> ECU ?
> 
> I guess I could suck it and see but I don't want to melt my ECU if it can
> help it.
> 
> I guess what i am asking is what is normal impedance of TBI injectors used
> in 808/165's
> 
> The TBI i am wanting to play with is off a Aussie FORD EA 6 cylinder Single
> point if anyone is interested...
> 
> P.S
> 
> I don't want to build a external injector driver or modify the ECU.
> 
> Thanks
> Stuart Bunning..
> 
>