Prob a dumb question but how does it work. How does it know when the fuel press is to low. How do you set them. Sorry...just trying to learn and have no idea how they work.

 

they tap into the fuel system and have an internal device that can sense pressure if it drops too low it will break the connection between the 2 terminals.

They are set by a screw on the end of the unit.....they will be adjusted to the normal flowing fuel pressure of the vehicle they are installed on.

Hope this helps.

 

how do you adjust them to the normal flow ? and dont say by turning the screw..lol how do you know how mych to turn the screw?

 

Put an ohm meter across the 2 terminals. When it goes to OL, the circuit has opened. When it's zero or near, its closed.

 

what reading is OL?

 

Outside Limit, basically means the resistance is too high to measure, ie the circuit is open.

 

Definately need to check it. Mine was way off out of the box.

 

Does anyone know what the correct fuel pressure setting should be on the FPSS for a stock fuel system?

 

Most say around 35psi. Mine's at 40. Put it on a air compressor, dial it up to the pressure you want, adjust screw until it breaks circuit.

 

is there another fpss that is better than the generic hobbs one? mine keeps on acting up. i don't think it's my pump because afr is still good and and inj DC is good too but it feels like the nitrous keeps cutting in and out. or could i just have a bad one? fuel filter is less than 10k miles. 82k on the car.

 

Although I've never taken a hobbs switch apart, I can tell you they are extremely simple in design. It's one of the things my company makes, but to go on aiplanes. Pretty much every plane in the sky has our switches on them. There isn't a lot to fail on them other than seals, usually from over pressure. I would check the pressure setting before jumping onto more expensive stuff. You can also bypass it and see if everything works fine without it. That will tell you.