kevleetee

I thought that running a carb and electric fuel pump would be easier! I ran a Holley blue pump, then went to a quieter Carter 12v pump, got me one of those $40 Holley regulators and a fluid filled pressure gauge. My problem is the mechanical fuel pressure gauge slowly decreases psi from 7psi at start up down to 0 once up to running temp, yet when I pull my float bowl screws I still have fuel. The pump is still running and everything seems correct but no gauge psi. Who makes a gauge that will function correctly with normal under hood temperatures?

speedtigger

iTrader: (16)

You and everybody else who has tried to run a liquid filled gauge under the hood. I really don't know why they even make them. Just pull the little rubber plug out of the back of your gauge and let the liquid out and it will work fine.

dealrcn

X2 on what Speedtigger is saying. When the fluid gets warm it gives you false readings cause the fluid is pressurizing the gauge canister. Pull the plug and drain it.

ignatz

kevleetee: Same here those are useless. I installed an AEM pressure gauge in the cluster area of my vette, same year as your Camaro to see what was happening under load. That works well.

And … now that I have your attention, do Camaros have fuel return lines like Corvettes of that vintage? I had no success with a Mallory fuel log /regulator, I think because of an undersized 5/16" return line. Once you figure something out I will be curious to hear more.

Right now I am dead headed but would like to have the fuel recirculating.

cruisin'73

iTrader: (8)

As usual, awesome advice speedtigger! I have a liquid filled gauge mounted to my carb fuel rail and when the engine gets warm the needle jumps up to 14, then settles to 7 and bac and forth and back and forth…I’ve pretty much written it off. I’ll try draining it and see if that helps. THANKS!

kevleetee

I have a single fuel tank pickup but plan to upgrade it with a new vented pickup and using the vent side for a return and adding a steel return line back the frame . My setup is dead headed and my carter fuel pump runs around 115-120 degrees, hopefully by adding a return line it will keep the pump and fuel running cooler. I drained the fluid out of the gauge and it is reading correctly but due to the temp the fuel psi is 0-1 psi when up to temp.

ignatz

Thanks - the little I learned about regulators is they work best if there is no back pressure. So you want your return line to be at least as big as your fuel source.