I have a 91 crx. It has a 93 Ex computer in it and I wired the harness to be a DX to Si conversion. Then I bought the Hasport shorty subharness that goes from the stock ECU connectors to the 93 EX ecu. But in order to run the 93 Ex ECU I had to wire the Injectors a so(or so says chiltons) Injectors 1-4 red yellow blue and brown to pins A1-A4. Then all four ground wires either yellow/black or black/yellow I grounded to a bolt in the engine bay. Before I had these wires on a 90 crx si resistor box and it wouldn't even run. Now that I got it to run I blows a fuse. Number 14 or the alternator something something that I cant remember right now. Any answers? Thanks

 

on a 93 civic harness the grounds for the injectors dotn ground to teh motor, they ground to a connector by the clutch resivoyr. ground it to thebody and seeif it makes a diffrece.

 

The yellow blacks are not grounds they are power. They are supposed to receive power from from the resistor box which recieves a +12v signal from the main relay when the engine is cranking or when it primes. The ecu supplies the injectors with a pulsing negative(ground) signal from the 4 injector wires to make them fire.

 

exactly

 

they ar not suposto get power from the 12+. They go on the backsie fo the injectors (-side) and then ground to the car at some place. the box SHOULD NOT go between the ECU and the injectors or it will not work.

 

SO in simpler words the colored wires go right to the ecu and the yellow/black wires ground right on the body

 

tehy ground somewhere on the body. Just take a multi meatera nd do a continuity test between the yellow/black wire on the injector and then on the pins on the back of that connector by the firewall. Dont worry i have the electrical diagram of the entire car and that is a GROUND.