zacht

iTrader: (18)

ok, car is 98 WS6 with a 02 motor and LS1 intake. i checked the fuel pressure today, and when i turn the key on it goes to 50 psi, little bit low. according to the manual it says once i start the car it should drop 3-10 psi. from 58 psi (stock, mines supposed to be) it would make it 48-55psi at idle, normal operating temperature. when i start my car it jumps to 62-63psi, i know i have the 98 with the return system and a rail regulator.

the hayes manual says fp over 60 psi is a problem (probably not for modded or FI cars) even when i blip the throttle it doesnt move from 62-63 psi.

any ideas what my problem is? im thinking regulator right now.....

waldershrek

iTrader: (1)

If the car is running fine I wouldn't worry about it

samson_420

iTrader: (1)

You are talking about 3 Psi over spec. . . . Who cares.

How is the car running?

zacht

iTrader: (18)

yeah, it seems to run fine, minus the fact i need a tune, i basically have full bolt-ons now and throwing all sorts of egr/air/02 codes. theres a slight stumble around 23-2400 rpms, but i know i need a tune.

i know its nothing big to worry about, im just worried about why the pressure goes up 13psi when i start the car. text books say it should drop when you start the car, anybody know why it goes up when i start it?

im throwing the good ole p0300 code (random misfire) and im thinking this could possibly be whats going on.

406malibu

check your O2's they will cause a random misfire. also, how do you have an 02 ls1 without an LS6 intake?

zacht

iTrader: (18)

the previous owner put in a new crate motor, still kept the LS1 intake. the LS6 intake is pretty much my last bolt on. i ran the numbers on my block and its a LS6 block numbers 12561168 (iirc) and it has 241 heads. so i know its a 01-02 motor. also i think he kept the LS1 intake to keep the egr.

yeah, ill mess with the O2's, my passenger side is showing low switching and slow heating, but i eliminated the air and egr.

zacht

iTrader: (18)

theres gotta be a fuel system guru out there......

zacht

iTrader: (18)

ah, did i put this in the wrong section?

zacht

iTrader: (18)

thanks to whoever moved it!

zacht

iTrader: (18)

to the top...... someone's gotta know

Ouija

iTrader: (3)

I've been chasing gremlins in my 01. (routinely a P0171 & P0174, and randomly P0300, P0440, P1416)

I hooked up my fuel pressure guage and it sits @ 50psi in "on" @ idle i'm arround 60psi, when turned off it sits back @ 50psi, and it takes about an hour and a half to drop 5psi.

Everyone I've conversed with states they have very similar results.

I doubt you are having fuel pressure issues, and I think the manuals are wrong.

No one I know recalls EVER seeing a drop in PSI with the car running.

1987firechicken

^^ Yup I have a permanant mounted fuel pressure gauge and it does the exact same thing yours does.

Key on - Pressure hits about 58 and drops to around 50. Fuel pump is priming the lines not running creating pressure the whole time or it would kill the battery.

Key turned to cranking - Pressure jumps to the 60 range and stays put until I kill it. Again now the pump is running and creating pressure until you shut it down.

I would be very concerned if I saw any dip once started which would point to injectors leaking down between firing or the more probable dieing fuel pump. I don't like to starve my engine of fuel and start melting and breaking ****.

zacht

iTrader: (18)

ok, then im not overly concerned about it, maybe its my 02's throwing the p0300. ill have to change them out for new ones.

thanks