Cliff's Quadrajet Parts and Rebuild Kits

General Category => Quadrajet Carb Talk and Tips => Topic started by: Cadman-iac on October 03, 2025, 03:36:55 PM

Title: Optimum fuel pressure
Post by: Cadman-iac on October 03, 2025, 03:36:55 PM

Now that I can adjust the pressure, is there an optimal setting, or is each vehicle different?

Title: Re: Optimum fuel pressure
Post by: Cadman-iac on October 08, 2025, 10:02:40 PM

  What I'm asking is, where within the 3-9
 PSI that the Quadrajet is able to function well is the optimum pressure?
 I've been going from 4.5 PSI to 7 PSI,  and i haven't really noticed any difference in how the carburetor performs, but I'm wondering if you have your pressure set on the lower side if you will experience any fuel starvation at WOT.

 If you run a lower pressure, like 4 PSI, (and according to Cliff the pressure changes the fuel level), should you, or can you,  set your float level just a bit higher to compensate for the lower pressure, or, if you opt for a higher pressure, (say 8.5 PSI) should you set the float at a slightly lower level?

Title: Re: Optimum fuel pressure
Post by: lightning boy on October 09, 2025, 01:08:37 PM

17058218 run at 6 PSI float at 9/32" runs great.

Title: Re: Optimum fuel pressure
Post by: Cadman-iac on October 09, 2025, 01:49:39 PM

Quote from: lightning boy on October 09, 2025, 01:08:37 PM

17058218 run at 6 PSI float at 9/32" runs great.

 Is that with a mechanical pump or an electric one?

Title: Re: Optimum fuel pressure
Post by: lightning boy on October 10, 2025, 12:43:04 PM

in tank elec. with regulator

Title: Re: Optimum fuel pressure
Post by: Cadman-iac on October 10, 2025, 12:52:59 PM

  I'm currently running at about 5.5 psi with the float at 13/32. I think I'll try a slightly higher float setting and see what happens.
  Does your pressure fluctuate with the temperature?
 Thanks for the reply.