garys 68

iTrader: (1)

Does anyone use a Hobbs switch to shut off fuel with loss of oil pressure?
And if so, is there an bypass terminal on the LS starter to wire into the switch?
I've always used them for electric low pressure carb pumps, but have not seen any mention of that in this forum.
Gary

Rodder

iTrader: (2)

people traditionally use an oil pressure switch as a way to approximate whether the engine is turning. The PCM can tell directly whether the engine is turning by looking at the crank sensor, and it turns off the fuel pump if the engine stops turning. Most people use the PCM to control the fuel pump.

bczee

iTrader: (12)

Like Rodder said. Used a Oil pressure switch to a relay for the fuel pump. That is what I did for my 84 Z28 when I converted over to a in tank pump.

Pop N Wood

iTrader: (1)

My starter didn't have the bypass lug. But it was a simple matter to put a 14 guage lug onto the main starter wire on the starter.

Rodder

iTrader: (2)

with a diode I hope? That'd kinda suck if your RUN circuit powering the fuel pump relay was also trying to spin the starter...

Pop N Wood

iTrader: (1)

No, with an oil pressure switch to connect power to the pump from either the starter or a switched circuit.


http://www.mr-gasket.com/pdf/7872.pdf

Rodder

iTrader: (2)

ahh, I was thinking SPST instead of SPDT

garys 68

iTrader: (1)

I'll be using the computer wiring harness to run the pump too.
I just didn't realize the computer was that smart.

Rodder

iTrader: (2)

The stock GM PCM is pretty sweet...