fuel pressure question
Thread Starter
Staging Lane
Joined: Mar 2014
Posts: 50
Likes: 0
fuel pressure question hi everyone , i know i could have post this treads somewhere else , but here look like there is more traffics thanks for understanding
last sunday
i drove my truck , everything was going well.
and soon as i get off the freeway it dies on me.
fuel pump was not priming anymore
i turn on and off multiple time the system and finally the fuel pump started to working and i was able to get back home
but the engine was running king rough , glad i was ony a block away
the pressure was only about 45 . i probe the fuel pump and the max was 45 psi
next day after work i jump on it to do more diagnos
to find out now
when the computer prime the pump it is still 45psi
now if i probe the pump i get 60psi , i stop the pump and goes back right away to 45psi
i probe again the pump , get 60 psi , while the pump running I clamp the fuel line before the rails , turn off the pump , the pressure stay at 60psi = that tells me the bleed off does not come from my injectors
engine dont start unless i press gas pedal , and it will run bad like miss firing or something
now question
could it the pump only ? does that happen a fuel pump stop working and work again?
or a mix or fuel pressure regulator and fuel pump ?
does a corvette styl fpr can work with a pump delivery 350 LPH ?
fuel pump is a walbro inline brand new , gsl396 350lph
i have a corvettle fuel filter regulator ( i had a walbro 255 previously with same system and never had an issue , only change was this new walbro 396 )
return line back into send line ( ls swap conversion)
any ideas?
last sunday
i drove my truck , everything was going well.
and soon as i get off the freeway it dies on me.
fuel pump was not priming anymore
i turn on and off multiple time the system and finally the fuel pump started to working and i was able to get back home
but the engine was running king rough , glad i was ony a block away
the pressure was only about 45 . i probe the fuel pump and the max was 45 psi
next day after work i jump on it to do more diagnos
to find out now
when the computer prime the pump it is still 45psi
now if i probe the pump i get 60psi , i stop the pump and goes back right away to 45psi
i probe again the pump , get 60 psi , while the pump running I clamp the fuel line before the rails , turn off the pump , the pressure stay at 60psi = that tells me the bleed off does not come from my injectors
engine dont start unless i press gas pedal , and it will run bad like miss firing or something
now question
could it the pump only ? does that happen a fuel pump stop working and work again?
or a mix or fuel pressure regulator and fuel pump ?
does a corvette styl fpr can work with a pump delivery 350 LPH ?
fuel pump is a walbro inline brand new , gsl396 350lph
i have a corvettle fuel filter regulator ( i had a walbro 255 previously with same system and never had an issue , only change was this new walbro 396 )
return line back into send line ( ls swap conversion)
any ideas?
Last edited by vincentnova; Mar 11, 2024 at 10:10 PM.
TECH Fanatic
Joined: Jan 2009
Posts: 1,067
Likes: 477
From: Bostwick, GA.
Voltage at the pump is?
What is it when you probe it?
That filter/reg is becoming a problem for many users.
A volt drop test is in order, as is a review of all electrical connections including the grounds.
What is it when you probe it?
That filter/reg is becoming a problem for many users.
A volt drop test is in order, as is a review of all electrical connections including the grounds.
