the fuel pump control ground in the ecu intermittently is inop, its the ground for the coil in the main relay that swings the arm over for the fuel pump power. My question is if i cut the wire and just run it to a solid ground will it effect anything else? I assume fuel cut would involve cutting power to the injectors, not the pump, so i'm good right?

 

You are correct, there are two relays in the main engine relay unit. The FP half only controls the FP.

If you have some further in depth electronics understanding it takes more amps to pull the switch closed than it does to hold it closed. If you are loosing your control switch then just replace the main relay. Isn't it around 50 bones, it is a high wear and tear item and the other half will go out in short order. If it is dying while the pump is running then it is bad from its own generated heat and loosing its own magnatism ability. If the main ECM is not controlling the ground then I completely understand why you want to give it a permanent ground.

If the relay is weak then just stuff a 16G jumper wire at the two switch terminals if you dont want to buy a new one.

Duane in Japan

 

that would make the fuel pump run as long as the igntion switch was on. Could cause some safety issues. Sure it's not a main relay problem?

 

the main relay tested good, when the car was not running there was no ground at the harness with the main relay disconected. I tried it with the ignition on and while cranking. This car was given to me because the guy couldn't get it running. I found a orange connector by the intake tube to be disconnected and it fired right up. I proceeded to take apart the drivers door to fix the regulator. With the door lock and window switch disconected i went to move the car and it wouldn't start. No power at the fuel pump because of that missing ground from the ecu to the main relay. Put the door back together yesterday and it fired right up. Would the door effect this? I wouldn't think so?

 

nOT GIVING ANY SPECIFICS AT THIS TIME, but the door does deal with the main relay but only on hot days. When the car is completely closed up and pretty hot on the inside this is the scenario when the relay will not work. The simple act of opening the door or lowering the window for several minutes will allow the hot air to escape in turn allowing the engine to start via a cooled down main relay.

All orange connectors deal with the anti lock brakes so that was not the reason for the engine starting on that attempt. Yellow connectors deal with the air bag system. Good luck.