fuel pressure problem ='[

[darkslide]

so i tried checking the fuel pressure on my kade because im running rich and still haven't found my problem, i found that i was getting 41 psi at idle and during acceleration, so i checked the pressure regulator and it held vacuum. then i read in the factory service manual and it said "Don't preform a fuel pressure check while the fuel pressure regulator control system is operating; otherwise, fuel pressure gauge might indicate incorrect readings"
i've been looking and do not know what a fpr control system is, wondering if anybody can help me out!?

[Z U L8R]

your fuel pressure is not making you run rich, check your timing see if it's retarded, other than that the ecu controls the a/f ratio via different references from different sensors

such as, maf, coolant temp sensor, o2 sensor.

for the record, i've never used an aftermarket fuel pressure regulator. i don't see the point. you either flood your motor from idle to redline, or you starve your motor from idle to redline. why not just tune the air/fuel ratios and adjust timing through out your power band with a piggy back or a stand alone system...
gl,
Dave =]

[darkslide]

cool ill check the timing, probably the only thing i havent checked. but yeah i checked the tps, map, ect, and 02, which all came out good, so that led me to check the fpr. also still wondering why my fuel pressure was reading approx.. 41psi @ idle instead of norm 34psi (or at least what the factor service manual says)?

[Z U L8R]

did you check the fpr like the fsm says tho? did you check it with and then without vacuum going to it?

sounds like you're at least trying to fix ur car. i hate helping helpless ass buttassfaceholes that are too lazy to check the shit you tell em to then sit their and cry that their car doesn't run.

all in all 3-8psi more fuel pressure than normal shouldn't make ur car unmanageable. it'd be different if you said you had like 60psi going to the rail hehe.

adjustable fpr = waste of money imo, until you get more than 500+

gl man,
Dave =]

[darkslide]

thanks for ur help =] , yeah i checked w/vacuum & w/o vacuum, just confused when it says; "Don't preform a fuel pressure check while the fuel pressure regulator control system is operating; otherwise, fuel pressure gauge might indicate incorrect readings"
i dont know what "fuel pressure regulator control system" is ='[ so im sure my readings are incorrect

this all started when my idle was stumbling and then it got worse die out at red lights and when i would let go of the gas n start to accel again its would backfire like crazy around 15%-30% thorrtle =/

[Z U L8R]

that sounds more like a maf starting to go bad or just getting a little dirty. clean it off and see if it helps.

np man,
Dave =]

[darkslide]

ill try that, is brake cleaner safe to use on it?

[UNISA JECS]

Originally Posted by darkslide

cool ill check the timing, probably the only thing i havent checked. but yeah i checked the tps, map, ect, and 02, which all came out good, so that led me to check the fpr. also still wondering why my fuel pressure was reading approx.. 41psi @ idle instead of norm 34psi (or at least what the factor service manual says)?

41psi at idle could be a few things:

1) You base static fuel pressure is abnormally high, there are a few reasons for this:

a) You have a adjustable fuel pressure regulator and set it incorrectly

b) You have a leak somewhere in the vacuum line leading to the fuel pressure regulator

c) Your fuel pressure regulator went bad

d) Your pistion rings are shot to shit and or you have some crazy ass cams therefore making your vacuum weak.

Note: If you have a vacuum gauge you can moreless exact what your fuel pressure should be at idle/vacuum.

Example:

My base static fuel pressure is 43.5psi "NO VACUUM"

My car pulls 21in/hg @ idle "FULL VACUUM"

21in/hg is equal to 9.3psi

43.5psi minus 9.3psi = 34.2psi

34.2psi will be your fuel pressure at idle "FULL VACUUM"

BINGO!

But first you have to know exactly what you base static fuel pressure is.

[UNISA JECS]

Originally Posted by darkslide

"Don't preform a fuel pressure check while the fuel pressure regulator control system is operating; otherwise, fuel pressure gauge might indicate incorrect readings"
i've been looking and do not know what a fpr control system is, wondering if anybody can help me out!?

That simply means unplug the fuel pressure regualtor "vacuum source" when checking base static fuel pressure.