okay. im doin dpfi to mpfi and using obd1 injectors. for each injector, if one wire goes to the ecu...is the other one ground? cause im also wondering if it would be safe if i grounded all four wires.

 

I know for sure that with the OBD1 versions of the P72/P30/P28/P08/P07/P06/P05 the other side of the injectors run to 12Volts at the drivers shock tower through a group of yellow/black wires.
I'm pretty sure that all honda ECUs are wired that way, but I'm not 100%

 

The injectors get their power from the main relay through the injector resistors. That's the yellow/black wires. The ECU grounds the injectors to trigger them. Do not ground any of them yourself.

 

cool. thanx for the info