I am converting a TBI harness to a speed density TPI harness. The TBI only had one wire for each injector running to the ecm. Where on the pin out i have lists two wires for each bank of injectors. The ones that i don't know about are the injector low drive. What exactly do these do. Do i need to run the second half of the circut back to the computer or is it just a 12 V source like on the TBI?

 

You might be better off posting this in the DIY Prom board giving they know alot about the pin outs on the 730 ecm. Or you could try and PM "Trickster" on the Electronics board. He knows ALOT about the wireing system on our cars.