24# Injectors.. stock heads/cam, what fuel pressure?

ARed1995GT

New Member
Dec 9, 2003
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Boca Raton, FL
I have all the mods in my sig.. whats an ideal fuel pressure for my car. Right now it is at around 33 psi, before it was at 38ish and it seemed to be running wayyyy too rich. I was told that the car will run rich at idle with longtubes.. but once you go wot it will lean out a lot... what do you experts think my fuel pressure should be at? or around what.. 33 isnt too low is it?
 
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It really Is hard to tell with those bigger injectors. I recommend you get a bigger fuel pump quick to get the pressure back up. If the pressure dropped from 38-33 by swapping your injectors the fuel pump is being overworked...

Go for a Walboro 255lph pump if you plan a power adder in your future. If you don't a 190lph will be fine. While you are under there change your fuel filter!
 
I would think 33 is a good place to start...I would be doing some plug checks for a look/see as to whats happening...Its old school but at least youll see if your to lean and can up the pressure accprdingly...

When I added LTs I used this method...it was puking Black smoke, the tell tale sign...i dialed it back to 26 then did daily plug checks after driving it...kept inching it up til i liked the plugs...whipping out an o/2 can be another sign...
I used this method til i dyno'd it...i was 4 lbs heavier than need be...but it was safe..til you get to a dyno, it'll suffice...
I wouldn't go stomping on it to hard til you verfify the plugs....mine were screamin White the first day.... :bang: Not good... :D
 
If your MAF is calibrated for the 24# injectors, set the pressure to 39 psi (stock, and what the injectors are rated at). The EEC is trying to learn all the time, and screwing around with the fuel pressure is just going to mess it up. The only time you need to change fuel pressure is if your injectors are too small and you'd like them to act like bigger ones. Lower the pressure too much and the fuel won't atomize properly, making tuning problems even worse (and if you squirt enough wet fuel in there, you'll wash the oil right off the cylinder walls...)

For what its worth, I run 39 psi on my 95, and I have 30# injectors. AND longtubes :).

Dave