Holley Fuel Regulator not adjusting
 

Hello I just installed a new Holley 12-840 fuel press reg on my 70 C10 with a 350. I am running a summit carb and it is needing around 5 psi of fuel pressure. My Delco mechanical pump is putting out 9 psi So I installed a regulator. Problem is that it is not adjusting properly. Initially it was reading 6.5 psi. I tried to lower it a little and nothing happened. I drove it for about 20 minutes and then the pressure showed 2 psi. I tried to bring it back up and nothing happened no matter how far I adjusted it. I shut it off and let it sit for about 30 minutes the restarted and it was a 5.5. Anyone else experience this? I feel like I remember reading something about holley having a ball valve issue maybe. I don't know.
Thanks,
Brent

Re: Holley Fuel Regulator not adjusting
 

I would take it apart and inspect it for debris and smooth operation. It sounds like you may have debris in the fuel lines.

Re: Holley Fuel Regulator not adjusting
 

Also get your gauge checked, if you are using a fluid filled gauge the readings can be affected by heat from the motor, headers etc which could be why after leaving the vehicle for 20 minutes changed the reading..

Re: Holley Fuel Regulator not adjusting
 

The behavior you describe of the regulator makes me wonder if the pressure adjustment should be made with no pressure in the system, adjust part of a turn then start up and test the pressure, repeat. The manual doesn't mention that, but it would not surprise me if it worked that way. It may be worth a try. Others with more experience may know better than me, so if my idea is just wacky you all can just tell me.