fuel pressure

[SC HYBRID]

i just installed the gauge on the fuel filter and my initial pressure was 48,then i adjusted the jr fpr and set it to about 60 with the vaccum connected,and then disconnected the vaccum,and it jumped to like 78.i heard i should set it to around 60 with the vaccum disconnected.is this true,won't my pressure be approx.40 or something after connecting the vaccum back.i need help.
also,if i adjust fuel pressure to say 70-80 baseline,could i raise my timing up to 14-16 degrees?does this make sense?more fuel=more spark? thank you

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[redline]

You should set it and 60psi with the vac line off the JR FPR. There is NO WAY your fuel pump will keep up with the pressures they way you have it set. Read some of the threads that Holden started. He got a better a/f with less pressure!

If you want that much timing back then you have to buy a BTM, ITC, PMS or something like that.

[SC HYBRID]

yes,holden,my fuel pressure is like 58-60 with vaccum connected,and like 78 with it disconnected.hope this info helps ya.

[Holden]

Your pressure is really high. You should lower it. Your mix will get richer and you'll put less stress on the injectors.

58-60 baseline/no vacuum is a good place to be.

[Holden]

What redline said is true. Factoring out my FPR, which is crapping out and getting "sticky and lazy", my mix got richer at WOT when I lowered the baseline pressure.

Mine was really high, 68 baseline and 99+ at 8psi boost on the gauge. I have the regular Walbro pump, which gives up at 85psi.

On the good, rich WOT runs I've had, fuel pressure maxed out at 81psi.

Jim told 58psi would be a better baseline (no vacuum) setting. Unfortunately, my JR FPR is messed up and won't go below 60psi baseline.

Are you capping the vacuum to the manifold? Or are you testing with a big vacuum leak?

I'm asking because jumping from 60 w/vacuum (idle) to 78 w/o vacuum is much more reactive than mine. Mine goes from 52psi w/vacuum to 60psi w/o vacuum. I pull the hose off the manifold and cap the fitting. You've given me one more reason to suspect my JR FPR needs to be replaced.

Good luck.