pboxfun

iTrader: (2)

When I hook up my fuel pressure test gauge and turn the pump on it goes to 43 psi and then immediately drops to 36 psi. It stays at 36 even when the car is on and idling. The pressure stays at 36psi while i rev the car at idle. But when I remove the vacuum hose from the regulator while the car is idling it goes to 43 psi. Do I have a bad fuel pump or is this normal??

shbox

Normal. You have to rev it pretty hard from idle for the pressure to change. It is dependent on the amount of vacuum and you have proven that removing the vacuum makes the regulator respond. So, I would say you're fine.

pboxfun

iTrader: (2)

Well thats good then! I thought fuel pressure should be a constant 43 psi and not drop to 36 psi

shbox

You don't need the same pressure at idle as at WOT. Idle pressure will always be lower if the regulator is doing it's job.

killagt

iTrader: (3)

why do you want to test it in first place ? any problem start the car ?

pboxfun

iTrader: (2)

No it wasnt that. I was testing it because of a problem ive been having with my car https://ls1tech.com/forums/lt1-lt4-m...lp-please.html

I was just making sure that the fuel pump wasn't the cause.