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Fuel Pressure

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bodymandave

20+ Year Contributor
36
1
May 6, 2003
WisconsinUS
Help!
what should the fuel pressure be in my car? i have an adjustable setup,but it something doesnt make sense. i got 550cc inj, and a 2g maf,
and the only way right now to get the fuel trims(tmo datalogger) to 100% is with my afc set at +17,then +15 across the board on low setting(30%), then its at +7 across the board with the high(80%). seems like everyone else is using - numbers. whats the stock pressure at and should i raise/lower it?im new to this and just learning, Thanks!
91 eclipse
9.5 JE pistons
16G
webcams,etc,etc, LOL
 
yea it does matter the 190lph pump will of corse rase the pressure on the line and cause the injectors to put in more fuel than intended..you have to compensate for this or lower the pressure..
 
so wouldnt what i want is to run stock fuel pressure, so that way i can turn the afc to a lean setting, so the ecu puts in more timing? i dont understand why with this fuel system i got that i have to richen up the afc..so confused.
what pressure should i have it set at ? whats stock?
 
I dont have my book handy so dont quote me on this but i think 43psi is stock, not completely sure though so i would get a 2nd openion..

if you have a fuel pressure regulator with a gauge on it you could always install the old pump and see what it registers and then the new one and lower it back down to the original.... :/ kinda a hard way to do it though..
 
go for 43 or so with the vac line off and with it on, it should drop to 38 or so. that is the stock setting for 1g's.
 
The 190LPH FP will not over-run the FPR like mentioned, it just won't run out of steam like the stocker does.

I see 40 PSI at idle (everything connected) and it should raise 1 PSI with every pound of boost.
 
Arrgh. Everyone, except for the last guy, is wrong.

the 190 lph pump will NOT raise the fuel pressure. It will flow more fuel, but it will still be within the range of the FPR's ability to keep pressure where it should be.

Stock fuel pressure on a 1g with the vacuum line off the FPR is 37 psi. With the line re-connected, that will drop into the low 30's.

To the original poster: you have some more serious problems to be dealt with.


...Kyle T.
 
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