Adding an electric fuel pump to my 76. Which wire should I rob power from? Thanks in advance. ME

 

Seriously ?
None. A electric intank fuel pump will run at around 9 amps. It should definitely have it's own dedicated circuit.
A inline (outside the tank) fuel pump is a really bad idea on every plane.
75-77 tanks are very easy to convert to a intank pump. Even with the bladder left in place.
But wire it properly. And make certain it's wired to kill in the event of a crash or roll-over.

 

Go right to the battery- you are already there.
Use a relay- and fuse it-
I recommend a fuse that uses a LED- so when it blows - you know it by simply looking at it- really easy in the dark!!!

 

There ya go, Richards the electrical expert on here. He shows an inertia switch. This works or switch your relay off your EFI ECU which will shut it down if the engine stops running. There are also other methods.

 

The Roll Over switch or Inertia Switch makes great sense as I had the experience of ending up on the side of the road with my drivers door on the ground. I remember opening my eyes after coming to a stop and seeing gasoline pouring out of my hood. The car was a Mazda Rotary engine and it had a BIG four barrel carburetor and en electric fuel pump. As soon as I could get out I did and then we pushed the car back onto the four wheels and turned off the ignition. I was sure that the car was going to end up getting toasted on the side of the road.

45 years later my 1968 C3 has fuel injection and I still don't have roll over protection. From what I have seen not too many people will survive an early C3 Corvette Rollover because the windshield folds down and you get crunched. Being tall makes the chances for survival even slimmer as the escape routes are fewer.

Thanks for your information Richard454, any suggestions on the "right" inertia switch to use in a C3? Where should it be installed? I really appreciate your help!!

I used to use an external electric fuel pump and ran it through a PWM controller that kept it quiet and un-noticeable. It just needs to be mounted properly to keep the system quiet. I do prefer the in-tank electric fuel pump for ease and convenience. With a chambered exhaust it is hard to hear the fuel pump anyway.

 

Nobody has yet asked what problem you are fixing or what new thing are you doing? The mechanical pump which stops when the motor stops is pretty much the safest thing you could hope for.

 

Have used inertia switch from Ford Escort Wagon. Simple, Cheap.

We had an RX7 with an OE 4bbl. 12A motor. Was by far most complicated carb i've encountered. Glad that car's gone; as well as its attached female.

 

I like the one used on the Ford F-150 - Mustang - Taurus - Ranger - Explorer in the 90's Part# F5AB 9341-AA

I mounted it inside the back storage compartment- near the battery- relay and wiring-

I'm also running a MS3PRO ECU that will shut off the electric pump if it drops below 200 RPM