Oil pressure switch

[plee4139]

I'm having and electric fuel pump installed and want to know if I need one of those switches to prevent the pump from running after the engine's shut off. I've reat that it's no longer necessary as the new pumps do that automatically.

[4NStudy]

If you wire-in the pump so that it is energized when you turn the key to the on postion, under normal driving conditions the pump will only run when keyed on. I had my pump wired this way when I originally installed it.

However, a problem could arise if one were to get into an accident, and for some reason the engine quit but the pump was still running. Not good in a roll over situation

When you integrate an oil pressure safety switch (or a roll over relay as some others have done) into the installation, the fuel pump stops running if the engine were to stop running after a serious accident. And that's a good thing.

[doug]

If it is using an oil pressure switch, you will not get fuel pressure until oil pressure is present. Do you have to crank the starter until you have oil pressure when starting the car?

[4NStudy]

The oil pressure safety switch has two circuits, one that's controlled by the oil pressure and another that you manually control with a momentary switch/button. The manual control allows you to energize the pump before the engine is running. I use the momentary circuit to fill the fuel line and top up the carb before starting the car when its been sitting for a few days. This step isn't necessary when I use the car regularly, there is enough fuel in the carb to start the car and run unitl the oil pressure builds up.

[swvalcon]

You should be able to get that switch from Summit racing parts.

[plee4139]

If it is using an oil pressure switch, you will not get fuel pressure until oil pressure is present. Do you have to crank the starter until you have oil pressure when starting the car?

Oil pressure is fine. The problem is I drive the car infrequently and have to crank in many times due to the fuel evaporating in the carb. I'm interested in the switch for safety reasons.

[plee4139]

If it is using an oil pressure switch, you will not get fuel pressure until oil pressure is present. Do you have to crank the starter until you have oil pressure when starting the car?

Oil pressure is fine. The problem is I drive the car infrequently and have to crank it many times due to the fuel evaporating in the carb. I'm interested in the switch for safety reasons.

[DEEPNHOCK]

Using the oil pressure safety switch is a good idea.
You can still wire in a momentary contact switch to manually run the electric fuel pump tp pre-charge the fuel system to fill the carb after long sitting spells.
You could also wire in a tip-over/impact switch that would kill the fuel pump circuit in case of an impact/accident.

https://www.summitracing.com/parts/mrg-7872

https://www.summitracing.com/parts/prf-80160?seid=srese1&gclid=CjwKCAiA0syqBhBxEiwAeNx9N8M2Nf-RQma5WGkoSCc9Ksv3A5o0n2JMkSJW1_6wnYT09EwEgl3ZqxoCthYQAvD_BwE

[BRUCESTUDE]

plee: I have an electric pump on my Lark, with the pictured oil press switch. After sitting a few days, it does take a some of cranking to get the carb full of fuel. I am planning on installing a momentary switch to eliminate this issue, which again, happens only when the car sits and the fuel evaporates. When I drive the car regularly, it isn’t an issue. IMHO the oil pressure switch is the necessary minimum safety device.

[enjenjo]

The MR gasket switch from NAPA ECH OP6610. Half the price of Summit and no shipping charge. Looking further this switch is no longer available from MR Gasket But summit may have some stock. NAPA shows 30 in stock in my DC.

You can run the bypass wire to the I terminal of the starter solenoid, only hot when starting. The wiring diagram https://static.speedwaymotors.com/pdf/5507872.pdf Use the I terminal of the solenoid instead of the ignition switch.