89mustangfive0

ok guys i have a mallory adjustabke regulator and i have an autometer fuel pressure gauge. i set the pressure to 40 with vacum off but i notice that when i hit the throttle the gauge shows the needle going down when i hit the gas. is that normal??

only90s

Does it go down when you are cruising or when you hit it wide open?

The pressure does drop at normal speeds due to vacuum...for example cruising around mine will drop to 35 or so...then when I hit it I will see 40psi until I get out of it again...

89mustangfive0

i dont no because its under the hood, but it drops to like 37 probably from v acum like you said