408 stroker fuel pressure dropping.
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Teching In
Joined: Sep 2024
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408 stroker fuel pressure dropping. In my Sonoma I have a 408 stroker full bolt on pushing somewhere around 500 hp running 91 with a direct import, nitrous fuel cell, external 255LPH pump, and 65lbs injectors. Car was running great about two years ago then sat untouched. Got back into it and it had all bad gas as well as clogged fuel lines and injectors. Bought brand new fuel 255LPH fuel pump(same one I had been running), Brand new Injectors, and cleaned out fuel cell as well as all the lines. Fuel pressure sits at around 45 at idle but drops around 10 or less and starts backfiring when the throttle is barely touched. Once off the throttle the pressure shoots back up and it'll run fine for a little longer. It's burnt out two fuel pumps now since I've been trying to diagnose the problem. I was wondering if I need to upgrade my fuel pump or if it seems like I'm having a problem with something in the circuit.
TECH Fanatic
Joined: Jan 2009
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From: Bostwick, GA.
In tank pump? Asking as you mentioned "fuel cell".
If so, look for a leak at the hanger connection hose.
Cavitation caused by poor/no tank vent will kill the pumps.
Low voltage will kill them, too.
Insufficient pump sock to bottom of the tank will cause cavitation, also.
Pressure may be sufficient as long as minimum fuel is called for.
" as well as clogged fuel lines". The hose liner may be failed, and a "flap" is pulled over the opening when hi volume is called for.
What kind of lines are you using?
Does the cell have foam in it?
If so, look for a leak at the hanger connection hose.
Cavitation caused by poor/no tank vent will kill the pumps.
Low voltage will kill them, too.
Insufficient pump sock to bottom of the tank will cause cavitation, also.
Pressure may be sufficient as long as minimum fuel is called for.
" as well as clogged fuel lines". The hose liner may be failed, and a "flap" is pulled over the opening when hi volume is called for.
What kind of lines are you using?
Does the cell have foam in it?
