Engine/Transmission (1994 - 1998) Overflow Valve...

[MHalloran]

So can someone tell me, how would our truck act if the overflow valve was wearing out or has gone bad and also, how does this part actually work? I did replace it at about maybe the 100K mark a few years back because I thought I should. Does the spring eventually collapse & wear out? Thanks for any answers. Mike

 

[Johnstra]

For a stock engine, I discovered by accident that it will run decent with no overflow valve at all. You'll have low fuel pressure, but the engine will run ok. Things you might see are fluctuating/low idle, gray smoke, stumbles. All the valve is supposed to do is keep the fuel return line closed until pump pressure reaches 22 PSI, at which point the valve opens and returns the excess fuel to the tank. Over time time the spring will compress and the valve will open at far less than 22 PSI. A bombed engine with larger than stock fuel needs will not run well (and maybe not at all) w/o a properly functioning OF valve.

-john

 

[PKemp]

Hmmmm... Someone in here has a post about an external over-flow valve. Eliminating the banjo bolt altogether and using a manual metering device that could set fuel pressure, concievably, to almost anything the lift (fuel) pump was capabale of.

Hmmmmmmm... . If you used an electric pusher pump and then put a pressure regulator on the output side of the injector pump... ..... Hmmmmm... . I wonder... ... ... Smooth, stable, constant and adjustable fuel pressure... ..... Hmmmmmmmmm... .

 

[biggy238]

See the thread about the banjo bolt in competition forum.



How the thing works. Its a bolt with a bore and small holes around the outside. The head of the bolt has another smaller bolt and a sealwasher. Under that is a spring with a ball at the end. When the engine RPM rises, a properly working fuel system will increase in pressure. To relieve excess pressure, the spring in the of valve is overcome by fuel pressure and fuel escapes around the ball into the return line. 22-25psi is normal. Some people remove it altogether and put in needle valves and or regulators and whatever they can come up with. Really though, if you have a fuel failure, the OF valve might be the only way you''ll have enough pressure to operate.

 

[bmoeller]

So can someone tell me, how would our truck act if the overflow valve was wearing out or has gone bad

http://dodgeram.org/tech/dsl/troubleshooting/injector_pump.htm#Overflow