Fuel problems

[stumplord]

I have found what appears to be efp shut off switch right beside the oil pressure switch and I need to know if there is an relay for the efp that is in the tank! Also where can I purchase the shut off switch? This is a problem I have on a 1986 Holiday Rambler with a 454 in it!

[enblethen]

No, there is not a relay in the tank. There a fuel pump relay under the doghouse mounted on a brace, left side of engine. It only runs for around 10 seconds to charge the fuel system
Most have the fuel pump power coming off the oil pressure sending unit. Check oil pressure sending unit. If it has three wires, it powers the fuel pump after getting oil pressure.
Oil pressure sensor is on the LEFT side of engine.
There is a knock sensor on Chev big blocks. They are single wire sensor.