Hi.. 88 5.0 x303 cam, stock ported polished heads, exhaust, headers, intake. these are the main engine mods on my car.. i just installed the accel adjustable fuel pressure regulator.... what should i set my fuel pressure at??? i set it to 45 psi... but im getting a hunting idle, sometimes car even stalls..... whats pressure will give me the best performance without the hunting idle....

also i wanna clarify something up.. when you set the fuel pressure you do it with the car idle-ing with the vaccum line off the regulator port right? im not sure if im supposed to take the reading with the vaccum port on or of. thanks for the help.

What are you running for injectors?

stock 19# injectors

fuel pressure is a funny subject its tricky
stock is usually around 40-42 but even that is a little high
but that is because the flow of the stock fuel pump is kinda weak.
try running around 35-38 give it a full throttle run and immediatly cut the car off and pull a plug to see how rich or lean it is running
its just patience with trial and error

[JUSTANG10]

What should my fuel pressure be at the lines before the reg on 91 mustang