fuel pressure test

[joakwin]

how do i doa fuel pressure test on my truck?

00 5.3

can i hook a gauge up to the crossover pipe where it has the alittle beed thingy on the passager side

and do i turn it on and run it at idle or rev it up and if so how much?

and what psi should i be seeing at idle or reving it up?


i have a p300 code and im trying to troubleshoot it to find out what could be the problem

truck has new injectors, fuel filter, plugs, wires

and air filter is good also


peace

[RedHeartbeat]

The bleed port that kind of looks like a tire valve or a/c port is where you test the pressure. Install the gauge on the connector and then turn the key on and leave it there. It should pressure up to 58 lbs and hold that level for at least 5 minutes without the fuel pump running. After that, start the engine and let it idle. Check for 58 lbs again. Pressure should always stay at 58 lbs. Next, rev the engine and monitor the pressure level. After that comes a driving test, pretty hard to do with the gauge under the hood though. It's best done on a dyno where a load can be simulated. If you have access to an electronic fuel gauge you could mount it in the cab and monitor the pressure. I don't know if anyone makes an extension hose for the fuel pressure gauge hose.

[joakwin]

<div class='quotetop'>QUOTE(RedHeartbeat &#064; Mar 11 2006, 11&#58;50 PM) [snapback]46792[/snapback]</div>

The bleed port that kind of looks like a tire valve or a/c port is where you test the pressure. Install the gauge on the connector and then turn the key on and leave it there. It should pressure up to 58 lbs and hold that level for at least 5 minutes without the fuel pump running. After that, start the engine and let it idle. Check for 58 lbs again. Pressure should always stay at 58 lbs. Next, rev the engine and monitor the pressure level. After that comes a driving test, pretty hard to do with the gauge under the hood though. It&#39;s best done on a dyno where a load can be simulated. If you have access to an electronic fuel gauge you could mount it in the cab and monitor the pressure. I don&#39;t know if anyone makes an extension hose for the fuel pressure gauge hose.
[/b]

looks like im gonna have to get some tape when i do this truck


im gonna do the test at the base auto shop because i don&#39;t have a gauge myself, been looking at sears online for a gauge and they have them for a good price, i think i may just buy one myself and do the test
be a way to let my wife let me get one

i think my fuel pressure is low or the regluator is going bad, but i hope not

im trying everything i can to figure out this p0300 code that seems to happen alot with nbs motors

laters

[joakwin]

<div class='quotetop'>QUOTE(joakwin &#064; Mar 12 2006, 12&#58;50 AM) [snapback]46795[/snapback]</div>

looks like im gonna have to get some tape when i do this truck
im gonna do the test at the base auto shop because i don&#39;t have a gauge myself, been looking at sears online for a gauge and they have them for a good price, i think i may just buy one myself and do the test
be a way to let my wife let me get one

i think my fuel pressure is low or the regluator is going bad, but i hope not

im trying everything i can to figure out this p0300 code that seems to happen alot with nbs motors

laters
[/b]

i went and picked up a gauge today so in a few mins or so im gonna go downstairs and do the test
i&#39;ll let u guys know the out come

[joakwin]

<div class='quotetop'>QUOTE(joakwin &#064; Mar 15 2006, 11&#58;09 PM) [snapback]47064[/snapback]</div>

i went and picked up a gauge today so in a few mins or so im gonna go downstairs and do the test
i&#39;ll let u guys know the out come
[/b]

i just did the test somewhat, didn&#39;t have to do a driving test because it was so bad from the get go

when i turned on the key motor off, the gauge went to 56psi
and then when i started the truck the gauge went to 52psi
and then when i rev it by hand, the 1st sec the gauge jumps up to 58psi and then goes back down to 52 psi


u were saying that the lsx motors need 58psi to run right, so im pretty much running super lean like crazy

so i need to replace my fuel regluator on the truck?


peace

[custom 68]

now wait here I need help too for clarification.
mine does just as described at idle it is at 52 when I blip the throttle it goes to 58 or so I know these regulators are vaccum changing so they go up with no vaccum that is why it can vary
so does this and joakwin&#39;s post sound right?
mine is a conversion with an external only fuel pump so I dont know what it is supposed to be other than what I read.
Dave

[joakwin]

<div class='quotetop'>QUOTE(custom 68 &#064; Mar 16 2006, 09&#58;40 AM) [snapback]47086[/snapback]</div>

now wait here I need help too for clarification.
mine does just as described at idle it is at 52 when I blip the throttle it goes to 58 or so I know these regulators are vaccum changing so they go up with no vaccum that is why it can vary
so does this and joakwin&#39;s post sound right?
mine is a conversion with an external only fuel pump so I dont know what it is supposed to be other than what I read.
Dave
[/b]

got the new reg installed in the truck and wow&#33;&#33;&#33; is all i can say, its like its a new truck, revs like a mofo,
i think it has more power now then when i got it 18 months ago, on my test drive, i was going about 25-30mph and then i floor it as hard as i can and i started to spin the tires, lol
i know thats not good but its kind of kool at the sametime, i have my winter tires on the truck right now(studded 245/75/16&#39;s) and my street tires are 255/70/16&#39;s, those will be going on soon

the truck has 84k miles

with the key off the psi is 58
turn the truck on and its at 56-57psi
rev it by hand and it goes to 58psi for a sec and then back to 56-57psi

[docone882000]

Sweet man.

[joakwin]

<div class='quotetop'>QUOTE(docone882000 &#064; Mar 16 2006, 11&#58;10 PM) [snapback]47177[/snapback]</div>

Sweet man.
[/b]

last night the code cleared itself
its still kind of acting up, this moring on the way home from the gym, the code came back up
and when i checked the fuel pressure and it was at 57psi

but then the fuel reg is making some sounds, like a hit and miss type of thing,

the fuel pump is new in the truck(nov from a dealer in san diego)
im gonna replace the fuel filter and go from their


does anyone know how much vaccum should be their at the fuel reg?
i can check that when i get off of work

[joakwin]

i got a T.O. for a 99 chevy truck from work
so it should be the same 99-02

the t.o. was saying it should have with key on motor off 55-62psi,
so with that info im i know my fuel pressure is good now

thats all i had time to read up on at lunch about the fuel reg

with the truck running the fuel pressure is at 62 psi

on the way home and to work the fuel reg is making a clicking sound, i can hear it inside the cab of the truck

when i got home i popped the hood and i could feel the fuel reg making the click everytime it did it, don&#39;t understand why its doing that

this weekend im gonna try and find out how much vacuum their should be at the fuel reg and test that

i know i have a fuel problem

i also need to find a cheap scanner to read codes, that will help out alot,
to bad i can&#39;t ground a few connectors on the port like how i could with my 93 tbi truck and count the check engine light flashes

peace