I'm having a problem getting my fuel pump to prime when it is cold. I've narrowed it down to the relay, I think. When I turn the key to start, I get 12v at the ECU to the fuel pump side of the relay, for approximately 4sec. I have power from the fuel pump fuse to the relay. I just can't get 12v to go to the fuel pump. I've changed out the relay and I still have the problem. When I'm having this problem the relay feels like it is working but weaker than when it is working. I know they have two coils in this relay. So could only one be working? I seem to have this problem when it is cold and it eventually runs after about 30mins of troubleshooting. Anyone have experienced this problem? What can I do or check? By the way its a 2001 ITR.

 

You're on the right track in your troubleshooting. The ecu will prime the fuel pump for 2 seconds when you turn the key to the "ON" position. What you need to do next is crank the engine while having the multimeter measuring voltage on the ouput side of the relay (pump side) and see if you're getting 12v to the fuel pump.

 

Thanks, will do.