When installing a low oil pressure cut-off switch, which is better:


1. Have the switch cut-off the ignition (power to the coil pack) ?

2. Have the switch cut power to the fuel pump?

 

Well, I couldn't wait anymore for an answer and went with the fuel cut-off when oil pressure is low or gone. I installed an oil pressure switch on a "T" of the return line into the remote filter adapter from Perma-Cool. The switch cuts power to the fuel pump and injectors if the oil pressure ever drops below 10 psi. I also installed a bypass switch in the dash that by-passes the pressure switch when starting the engine. Also an indicator lamp that comes on when the pressure switch is in the normally closed position (no oil pressure).
Now I feel alot better about my oil filter relocation. If, for any reason, I get an oil line break, or a hose comes loose, I know the engine is going to cut off when the oil pressure drops below a safe level. I'll try to get some pictures of the set-up and post them.

 

May I suggest you keep a diagram of all your doings so that when the truck doesn't start you remember how everything is wired. That has to be added to the diagnostic procedure for a no start condition.
BTW you had brilliant idea!

Regards

Jean Marc Chartier

 

Thanks for the compliment, but it's not my idea.
I have added the wiring mods. to my wring diagrams (it's not that complicated). Just cut the red wire going to fuse #18 in the Battery Junction Box and put the pressure switch in series with it and the by-pass across the switch. (This applies to a 2001, F150 Standard Cab, 4.2L).

Here's a link to a page that this guy did for adding an electric fuel pump to a carburated car.
He needed the oil pressure switch to ensure the feul pump didn't run when the engine wasn't. He gave the NAPA part number for the switch which cost me around $10.

http://bowditch.mit.edu/~curran/cars.../tankpump.html