Fuel pressure decrease wot

BioMechanic

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Installed analog fuel pressure gauge. 50 psi idle. Uopn throttle decreases to 20psi. Cleaned fpr screen now idles at 40 psi, throttle 15-20psi. Need help. Need fuel pressure.
 

79jasper

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If you have the money to do so, go efuel.
Otherwise you could have a weak fpr spring. You could try the bb mod.

Sent from my SAMSUNG-SM-G935A using Tapatalk
 

BioMechanic

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okay, just installed BB mod. now 60psi at idle and does not drop below 40psi WOT.

i guess my question is should PSI drop WOT? i would assume it would increase with throttle. more RPMs = more cam rotations = more fuel from mechanical fuel pump... right?
 

DaveBen

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Not really. You have maximum flow at WOT and that will cause the pressure to drop. Fuel pressure may come up a bit as RPMs increase.
 

Artpro

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okay, just installed BB mod. now 60psi at idle and does not drop below 40psi WOT.

i guess my question is should PSI drop WOT? i would assume it would increase with throttle. more RPMs = more cam rotations = more fuel from mechanical fuel pump... right?
Newby here. Pray tell, what is the BB mod??
 

DaveBen

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40 psi at WOT sounds about right. These engines do not make more pressure at higher RPMs. Faster fuel flows = more resistance and less pressure.

By the way, :welcome Artpro!
 

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