I have a 1995 4Runner 3.0 V6 and I'm having issues getting power to the fuel pump. I had one of the heads rebuilt and when I put it back together I couldn't get my fuel pump to work. After looking into it I found out it could be my circuit opening relay so I replaced that and it worked. Then a couple weeks later it was having issues again so I used a jumper wire and when I got it started I pulled it out and it stayed running. After this happened more often I replaced the EFI relay and it didn't do anything so I checked the power at the pump and when my key is at ON my pump gets no power even with a jumper wire, but when I turn it over the pump does get power. This problem seems to happen every time I turn my key to ON, however, the only time I have an issue starting my truck is when it gets warmed up then left to sit for a few minutes. I am not sure what it could be at this point as I have tried to research the issue but I have had no luck. My truck is also throwing code 12, which is an RPM signal. Could there be any connection between the two?

 

Jumper wire? Where?

The COR closes when EITHER the key is to start, OR the engine is sucking air through the VAF. So if the STA signal is not making it to the COR, or 1/2 of the COR is dead (there are two coils), it will STAY running once started (the VAF holds the COR closed), but won't start (the COR is open).

BTW, the correct place to put a jumper is between B+ and FP in the diagnostic connector; FP goes straight to the pump (no COR) and B+ gets power from the EFI relay with key-on. That jumper, then bypasses the VAF, the starter switch AND the COR.