I’ve been running trial and error with this car replaced the injectors, changed the injector 4 ground wire all the way from the ecu to the injector kinda just overlayed it to test if would work. Still same issue. With key on engine off injector #4 is constantly having ground and letting fuel in. Changed the main relay as well. Any input on what else i should check or how to rule out bad ecu or harness?

 

You can't rule out a bad ECU... you have just PROVEN that the problem IS the ECU. You likely have a failed fuel injector driver inside the ECU. There are companies that can repair your ECU (replacing the pair of fuel injector driver devices) and get you back up and running again... or you can track down another 30-35 year old ECU and pray it still works properly.

 

How is it that i proved its the ecu? I feel like it could still be that ground wire, i did a poor job just kinda for testing purposes, i just overlayed a new wire didn’t re pin anything or nothing, how much would a repair like that cost? I almost feel better just buying a different one with how long wait times are for ecu repairs.

 

The ground wire comes from the ECU. Power is applied to all four fuel injectors when the key is turned to the On2 position.

 

You were absolutely correct i swapped to a different ecu and the problem went away!! Thank you.