hey guys, my car is running really really lean at WOT. My 02's are in the 50mV range....they should be in the 850's!!

Now, a little background. I have a pretty annoying idle/surging problem that is probably a vac. leak. It does it at idle from like 800-1200rpm give or take, it is WORSE when the car is in park or neutral(better under load) and it changes its attitude as the car warms up...very weird. Sometimes, at night or in certain temperature it behaves pretty normal. And sometimes it is so ridiculous i shut the car off and wai a few minutes and restart hoping "i can trick it" LOL>>(joke's on me)

ANYWAY...a few months ago when i finally got the 383 in i set the WOT FP at 50 psi for starters(vac. line off regulator, etc).

Today I was trying to make sure i needed a fuel pump(unrelated to idle problem), but now I'm not so sure. I hooked up the FP guage and pulled the vac. line off of the regulator. Primed the pump (key forward) and the FP jumped up to 60psi! So i ask myself #1: how did the FP rise if i set it at 50 psi? #2 why did the car get slower and LEANER than before when i set it at 50 psi if the FP is now higher?

So, i purge the guage, do it all over again...same stuff.

Next, i started the car and HERE IS WHERE i know something weird is up>> the guage was bouncing around so rapidly and off the charts from like 40 psi off to over 100psi and off the guage. it was flickering back and forth like a mad-man! Unreal.

SO, my question is....what can be wrong with it and what is causing what to do what???????? Is this causing that or that cauing this....regulator shot???

I'm lost here...pretty new to EFI :/

 

Regardless of the pump, pulsation damper, filter, and supply line, if the pressure RISES above the setpoint, either the regulator is flaking out or the return line to the tank is restricted.