Is it normal for a return setup to lose pressure when turned off?
Thread Starter
8 sec potential, 12 sec slip
iTrader: (50)
Joined: Apr 2002
Posts: 4,092
Likes: 2
From: Savannah, GA
Is it normal for a return setup to lose pressure when turned off? Ever since I re did my fuel system and added a return line to it (used the stock EVAP as a return) I had to crank it 2 times for it to start up. Just the other day, I payed attention to my fuel gauge when I first turned it on after it had sat for a while (didn't turn the key all the way, so the starter didn't engage). Anyways, I noticed that the fuel pressure only went up to like 25 or 35 range. I cycled the pump again (turned the key off and on) and the pressure went up to 58, so I cranked it over, and it started first time.
So my question is if this is normal for a return system to lose pressure after being shut off? If not, I guess there must be a leak somewhere, but I have gone over the lines very closely, and under very close inspection, I can not see any fuel leaking out of any of the connections. This is what got me to wondering if it was just normal for all return style systems to lose pressure like this?
If there is a leak, I guess it would be on the feed side of the line, and not the return side, or could it be either?
So my question is if this is normal for a return system to lose pressure after being shut off? If not, I guess there must be a leak somewhere, but I have gone over the lines very closely, and under very close inspection, I can not see any fuel leaking out of any of the connections. This is what got me to wondering if it was just normal for all return style systems to lose pressure like this?
If there is a leak, I guess it would be on the feed side of the line, and not the return side, or could it be either?
I just installed my fuel system, with return as well. My pressure drops when the pump is off, as it should. My buddy thought it shouldnt but i just called and asked if the regulators had a built in check valve or something, they dont. I am assuming that production regulators/ fuel systems with returns must have a valve or something else to keep the pressure up after the 3 second prime that the computer provides.
In short: i have my inline pump controlled by stock fuel relay settings, so i have to start the car within the 3 seconds of priming and soon as the priming is done all the fuel will drain back.
basically whats to stop the fuel from returning? nothin...
In short: i have my inline pump controlled by stock fuel relay settings, so i have to start the car within the 3 seconds of priming and soon as the priming is done all the fuel will drain back.
basically whats to stop the fuel from returning? nothin...
Thread Starter
8 sec potential, 12 sec slip
iTrader: (50)
Joined: Apr 2002
Posts: 4,092
Likes: 2
From: Savannah, GA
Well, I have to prime mine twice to build up the needed pressure. But I guess if the regulator lets all the fuel drain back into the return line when the pump is off, that would explain it.
