The ME ECU range has several injection channels (4 on the ME221 Wire-In, 6 on the ME360 and 8 on the ME442 Wire-In/Plug-In) each of which is capable of driving several high impedance injectors. 


(An injector is considered to be high impedance if its resistance is larger than 12 ohms. Low impedance injectors are usually under 4 ohms impedance across their two terminals).  


Generally however, the ECU will use only four of these channels to drive injectors fully sequentially on a four cylinder engine.


The Injector should receive a switched 12V ignition supply on one terminal, and the second terminal should be routed to the required injector pin on the ECU.


You can also choose to wire the injectors in batch. You can run any number of injectors on a channel - as long as the resultant impedance does not fall under 4 ohms.


(Each Injectors Impedance) divided by (Total Injectors per driver/channel) equals (Total Impedance per channel)


To calculate this use the following examples as a guide:


We have 4 injectors, each being 16 Ohms:
16/4 = 4 :: OK to run on one channel.


We have 8 injectors, each being 12 Ohms:
12/8 = 1.5 :: Cannot be ran on one channel so instead, we can run the injectors split over 4 channels..


We have 8 injectors, each being 12 Ohms, and we intend to run them over 4 channels - the equivalent of 2 injectors per channel:
12/2 = 6 :: OK


If you plan to run LOW impedance injectors, then ballast resistors should be used. Please contact Motorsport Electronics Limited for more information on this.