90Lxstanger

That does sounds high, i run 36 psi(at least that what i was told from previous owner), im not lean or anything......
I found 39 psi on another site for base psi..............dont not about that tho......im sure a Haynes or Chilton would tell.

5.0stanger

Okay...now about adjusting to for optimal ratio...I would need it to be on a dyno to know for sure right? Starting low and working my way up would only be helpful on a dyno I am thinking.

morepower

my aeromotive unit said to set it to 42# right off the bat..seems to run good, when i bump it up to 50# once in a while it seems like a whole new car, much faster.

vristang

Stock fuel pressure is 38psi.
There is a little flex room for system tolerances, but 38 is the magic number.

Start at 38psi, and that is with the vac line off.


As for what happens when you adjust the fuel pressure...
The only thing you are changing is Open Loop; Cold Start (before the O2's kick on) and WOT.
During Closed Loop the computer is going to try and adjust for the added pressure, but it can only flex the pulsewidths +/- 12.5%.

If you add fuel pressure to enrichen WOT then you will have to dig into the computers 12.5% of adjustment during Closed Loop.
The opposite is also true - decreasing fuel pressure to lean out WOT will dig into the 12.5% of adjustment during Closed Loop.

During Closed Loop, if the AFR is still not at stoich after adjusting by 12.5% then the car continues to run either rich or lean.

hope that clears it up a little,
jason

5.0stanger

Got it running tonight, fired right up, set the pressure at 38lbs with vacume off to start. What should it be at with vacume on at idle? It was reading 28lbs