I have a 94 dx, 4 door, automatic, with only 134k miles on it. I bought it off a guy who said it ran fine but one day it wouldn't start. After I bought it, it started for me and I drove it home. Now it starts about 80 percent of the time, and when it does start it always runs properly. Whenever it doesn't start I can hear that the fuel pump doesn't fire. It seems clear that its an issue with whether or not the fuel pump gets power when I turn the key over. I replaced the main fuel relay and that didn't help. I'm hoping someone can help me out with what might be the problem cause I'm really puzzled by the fact that it works most of the time but sometimes it doesn't. Could it be the ECU?

 

Can you check that there is power to the fuel pump when the ignition key is turned?

 

Yeah, one time when it wouldn't start I put a volt meter on the contacts that go to the pump and it wasn't getting any power

 

Open up the main relay and re-solder it, even a new one can have a bad solder job. When it will not start, observe if the check engine light comes on then goes out when you turn the key on but don't crank. If it comes on and stays on it's either the main relay or the ECU.