Long story short....I had a 350 TPI, converted to 406 carb. I had a Speed Shop install a fuel system that includes a Holley external pump, 3/8" braided fuel line w/return, Holley Regulator, Filter & gauge.

One time I fire up the car it reads right at 5.5. The next morning it fires up & runs no different but gauge reads 2.

I adjust it back to 5.5 and then the next day it reads about 9. I drop it back down to 5 and it bounces all over, there is absolutely no consistency.

One instance it started up at 6psi, I drove to my destination where I stopped and parked for about 1/2 hour to pick something up, I got back in and it read 1 psi.

I'm not going back to the speedshop, we have not seen eye-to-eye since the project, customer service issues beyond control.

Thanks for your help!

 

Is the pump an electric or mechanical? Are you expecting it to hold 5 psi after you shut it off for awhile?

 

I just want it to be the same everytime the engine is running. . Electric inline external pump it is

 

Are you using a liquid-filled gague to read fuel pressure, by any chance? If so, pitch it straight in the trash and get a standard non-liquid-filled gague. 9 times out of ten, that's the problem in cases like this.

 

Yeah I was just going to suggest fault equipment also. Either the regulator or the gauge. A bad regulator would probably be more of something you would "feel" in how the car runs however.

Damon,
Why are the liquid filled gauges so bad?

 

Don't know. Just experience tells me they have always been flaky and continue to be flaky to this day. As recently as 4 months ago I had a buddy roll up in my driveway with similar "erratic fuel pressure readings" problem and it was the fault of the liquid-filled gague he used. Put my non-liquid-filled gague on (temporarily) and it read a steady 6 PSI under all conditions.

 

Thanks, ill move that direction....it is a liquid filled gauge