.25 seconds?

Mines 3 sec.

Mine is similar, key on it goes to 58psi then after prime settles to like 48 and will hold for a hr or two. Never really checked.

 

my fuel lab regulator and stealth 340 pump primes to 51psi first cycle but will bleed down fairly quick after

 

First step is putting a good fuel gauge on it and reading it after you shut it off, check it after an hour, 2 hours, ten.... in the morning after it sits overnight is the most important reading you need to do. You need to watch the Gauge as you flip the key to the run position. How much pressure does it build on that first hit? Thats what you want to see. 90% of the time, its just a weak check valve in the pump. The other issues i have seen are poor pump installs (pump to basket hose leaking or poor connection) In 17 years of being a mechanic I have seen injectors cause this also, BUT mostly in the older foreign cars, the injectors stick open when they fail. You would have a misfire immediately on start up if that were the case. (obviously not your issue)

The check valves in most of these pumps are hit or miss. Good or bad. It can be annoying.

I have a similar set up like Atomics. Dual Walbro 450's, -8 lines, big regulator, billet rails... I only run one pump most the time, the other just kicks on at 10PSI. Stock prime time on mine and it hits pressure immediately.

Get a gauge on it and report back.

 

heres that table I was talking about, 2002 OS

 

My table is zeroed out. I thought that was the delay time before the pumps primed up when the key was turned on.

 

I had no priming issues when I was running an Aeromotive regulator. The stock prime that happens when you turn the ignition on was more than enough to get the pressure back up from 0 psi. Started just like stock and bled down just like stock, around 58 psi during prime, dropped to 45 psi after prime, and bled off slowly from there. This was with a Walbro 400.

 

This is just my opinion on this thread. You dont need to be concerned with the pressure bleed down. You need to be concerned with gas draining back into the tank. That is was causes starring issues. The check valve in the pump or external keeps the line full of gas. When it primes the line is completely full so pressure increases instantly.

So in short the check valves purpose is to keep the line full.


Perhaps i am wrong. I dunno.

 

I agree with you Corey.

 

It says nothing about keeping the pump on longer in the description, only the time before it gives the priming pulse(s). Did you notice the pump run time changed? I read on another forum (I don't remember which), a guy said his OS had fuel pump prime time in the fuel system tab.

 

My OS has that.