Simple stupid fuel pressure adjustment question.

[1987 Six Shooter]

I've got an accufab fpr and wand to adjust the pressure to 43#. I know it has to be done with the vacuum line off, but does that line have to be plugged as well or left uncapped to suck vacumm. Sorry for the stupid question.

 

[MAK507]

I simply take the line off and let it hang there while I adjust. Directions don't say to plug it. I'll be damned if I'm wrong [emoji23]


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[1987 Six Shooter]

Its holding pressure, but as I rev it up, the pressure goes down if revved and kept at a higher idle. Isn't it supposed to go up?

 

[That GN Guy]

Reving the engine in park or neutral will cause an increase in vacuum. Rpm doesn't affect the fpr, vacuum does. You can hook an air line to the fpr and hit it with 8 or 10 psi, that should cause your fuel pressure to rise. Or drive it in the boost range.

 

[MAK507]

It goes up with each pound of boost


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[charlief1]

http://www.turbobuick.com/threads/read-this-before-you-post-please.384507/

 

[Heskahoka]

I've got an accufab fpr and wand to adjust the pressure to 43#. I know it has to be done with the vacuum line off, but does that line have to be plugged as well or left uncapped to suck vacumm. Sorry for the stupid question.

No, it does not have to be plugged. Pull the vacuum line, adjust to 43 lb, then put the vacuum line back on. When you put the vacuum line back on, you should see you fuel pressure drop 3-4 lb. or so.
I have the same setup you do and when I pull the vacuum line I don't plug it.

 

[earlbrown]

2 inches of vacuum is very close to 1 pound of pressure drop. if you hook a vacuum gauge up and see what it's pulling at idle, the decrease in fuel pressure should be right at 1/2 numerically of what the vac gauge reads.