Hi All,

I've been reading the threads on the OF valve for a few years now, and the major problems it can cause, and the routine failure of the unit.

Perhaps someone has asked this question, but why not just remove the OF valve and put a pressure regulator in the return line? If the OF valve is set to open at x amount of psi, and a person has an adjustable pressure regulator with a accurate gauge, why not just do that?

I think holley and some other fuel mfg. make some reliable regulators...

I would be willing to try a setup?

Just thinkin out loud,

Cheers

 

It would work fine but would require quite a bit of plumbing modifications on a steel line in an area with very little room to work.

 

Don't they work opposite? if the overflow valve opens at Xpsi, that means it builds it up to that and releases any more than that. A regulator would just keep it from putting and pressure higher than that past it. which means it would never build the proper pressure in the inj pump because it never closes. Kindof like the difference between a thermostat in your cooling system and those restrictor plates they sell to take their place in race cars. Just seems to me if the pump is meant to have that much pressure in it I'd leave it with that much pressure in it. Just thoughts, I may be wrong, often am

 

Infidel,

do you know the pressure that the OF valve is set at?

I have lots of time (I don't drive the truck in the winter) and have lots of tubing and fittings (An MS...) etc... from my Aviation days

 

I believe the valve is set around 23-25psi, but not 100% sure. See what bill says.

 

It's set at 25-28 psi but due to the simple construction of the valve can vary much more due to fuel use and rpms.
More I think about it simpler way to use an adjustable valve would be to install it on the return line back by the tank and substitute the o/f valve for a regular banjo bolt. This way you would have plenty of room to work. Downside would be that the return line would be higher pressure it's entire length which could cause a higher potential for leaks. Not sure, but this location might also interfere with the return flow from the injectors.

SmokinFive, if I get you right the type of regulator (like the type in a house) you're thinking of would regulate the pressure just fine but would cause higher pressure at the lift pump causing it to work harder. It also wouldn't supply the extra return fuel that flows though the pump cooling and lubing it. It could also result in fuel delivery lag due to having only the flow going to the injectors at the pump.
The regulator or has to be the type that drops pressure by diverting excess flow beyond the required pressure back to the tank. Sometimes these types are refered to as unloader valves or pressure sustaining valves.

 

Gotcha. I think im stuck on thinkin in Gasser terms, the old regulators used on carburated cars to keep the pressure down.

 

Thanks Bill,

Thats exactly what I was thinking, just putting another banjo on the pump, with alternate routing to the return line under the hood, with a regulator in between (still under hood),

I think I will give it a try, I can keep the stock sytem intact, and if the regulator it does not work, I will just throw the stocker back in...

If I remember right, if the pump gets to much pressure, it can cause trouble to?

Cheers

 

Keep us posted on how it works out. You are correct, too high of pressure, besides blowing things out can also cause poor idling.