fuel psi regulator

[rubicon]

With triple deuce carbs I set the fuel psi at the fuel log to 6psi. This seemed to be ok and won't know until I get it on the road if this will be the proper psi. I did this months ago and starting the engine up at different times through out the year I had no problems. To day I started it up and the pressure was up to 12 psi. I tried to lower the psi using the adjustment on the regulator with little success. Shut the engine off and bleed out the fuel pressure. Backed the regulator adjustment all the way out and started the engine. Pressure was down to 3psi. Moved adjustment back in to 6psi and everything seems to be ok. What would cause a increase in psi? The adjustment screw and lock nut were tight.

 

[Indycars]

Atmospheric pressure change would cause a small change. No idea why it
doubled in pressure, do you have more than one gauge that you can confirm
the fuel pressure with?

 

[railroad]

ethanol

 

[rubicon]

Only one gage. Seems fine now. Running 91oct. pure gas. First tank had 10% Ethanol. Added Driven fuel treatment with that tank.

 

[fletcherson]

I ran a tri power on a Pontiac for years with a stock fuel pump. I never had a issue with pressure, no regulator. The only issue I had was vapor lock. If you have all steel lines, the heat can cause the fuel to expand and increase pressure.