the car is a 00 ej8 with a b18c swap, I replaced the ecu because i had a problem with the fuel pump not priming so i replaced the ecu and everything worked fine forba couple of months but now the same issue again, ecu wont prime the pump. engine harness?

 

have you checked the main relay?

 

This^

...and

Did you check fuses 13 and 44?

G101 ground on thermostat housing?

Fuel pump ground wire?

Spark at the plugs?

CEL codes?

 

The car is not throwing any cel, it has spark and all the fuses are good. the main relay was replaced about 3 months ago because initially i thought that was the problem. i tried a friend of mines ecu and the fuel pump primed Normally but my ecu on his car did not work and fuel pump did not prime. but this this the second ecu, first one gave me the same problem

 

You may be blowing ECUs because some sensor connectors have been swapped. Check that before installing a new ECU.

 

That might be , im running a "tucked" style harness that i did years ago. Do you have any idea what resistors/capacitors control the fuel pump?