Why do I have high fuel pressure...

steve meltzer · #1 (**permalink**) 03-04-2017, 07:40 AM

WOW! Thanx Patrick for the tips and great info. I ordered the Carter FP and i do have the clutch head driver attachments, tho' having two 'Vettes with Holleys, i may just order the correct tool. More later. I can't get the car today and it looks like rain here in Houston tomorrow, so we'll just have to see when i can get the car. thanx again. s

patrickt · #2 (**permalink**) 03-04-2017, 07:55 AM

I think I could even lead my brother, who barely knows a screwdriver from a hammer, through a rebuild of a 4160. And over the last 40 years I've made every mistake humanly possible to make -- so I can see them coming and tell you how to avoid them. The first step, though, is to temporarily plumb a new pressure gauge right in front of the carburetor. The second step will be to conquer your fuel pressure issue. The last step will be to rebuild the carb with that kit. It's a better than fair chance that the 9psi that you were seeing resulted in the secondary flooding out by eating the needle/seat valve for lunch. So there's no sense in even touching the carb until we have a nice, clean, even 6psi feeding her.

steve meltzer · #3 (**permalink**) 03-04-2017, 09:12 AM

OK, home again. Gotta way and, with a proper automotive hose clamp, clamped off the aorta, oops, i mean the secondary feed line. With out the e-pump on, and after about 10 minutes of slow speed running the gauge again read 9 PSI! DX: bad mechanical pump, and it's on its way out! Opening the gas cap didn't change a thing.

When you seal the bowls to the body, do you put anything on the gaskets, like Permatex 518? thanx s

patrickt · #4 (**permalink**) 03-04-2017, 09:17 AM

Quote:

Originally Posted by steve meltzer

When you seal the bowls to the body, do you put anything on the gaskets, like Permatex 518? thanx s

No, absolutely not. We will use the BLUE gaskets that come in the kit and spray them lightly with silicone spray lubricant. Cleaning off the old gaskets is imperative. I like to use wooden toothpicks to clean off the old gasket material. Cleaning the needle/seat nut is usually the most time consuming. Never use anything that can scratch the metal.

steve meltzer · #5 (**permalink**) 03-04-2017, 09:25 AM

got thanx. s

steve meltzer · #6 (**permalink**) 03-04-2017, 02:49 PM

After I change the fuel pump, i was gonna drive the car and see about the pressure (secondaries to remain blocked). If it's a steady 6 PSI, then I was gonna tackle the carb, if not, check and probably impugn the gauge in the dash. Right?

And...when you change the fuel pump, I assume that, like a 'Vette, the engine needs to be a TDC for #1. Right? thanx steve

patrickt · #7 (**permalink**) 03-04-2017, 03:02 PM

Quote:

Originally Posted by steve meltzer

After I change the fuel pump, i was gonna drive the car and see about the pressure (secondaries to remain blocked). If it's a steady 6 PSI, then I was gonna tackle the carb, if not, check and probably impugn the gauge in the dash. Right?

And...when you change the fuel pump, I assume that, like a 'Vette, the engine needs to be a TDC for #1. Right? thanx steve

OK, we can skip plumbing in a new gauge... unless the new fuel pump starts pumping at 9psi too.

And you don't have to go to TDC at #1, just make sure the fuel pump arm is on the camshaft eccentric. Clean the old gasket off, and use a little oil resistant gasket goo on there.