Should my fuel pressure be and act this way on my 2009 Avalanche LTZ?

Hello folks,

I recently purchased a new to me 2009 Avalanche LTZ.  I have completed a lot of PMs on it and have taken a look at the fuel pressure with a gauge-after noticing my OBDII scanner was showing ~43psi (42-45 its back and forth) while driving home.  I am used to the older vehicles that seems to run higher pressue, but I know that this is a returnless system.  I am simply not familiar with how they are supposed to function.


I would appreciate it if you could take a look at this really short video clip I took of the fuel pressure gauge I hooked to the fuel rail.  It is rather erratic.

https://youtu.be/-MvmK406o80

Here is a photo of it still-framed.  The blurring of the needle seems to show the sweep.  It oscillates rather quickly.

http://i.imgur.com/dK0Mi9w.png

I have no trouble starting or anything.  No issues with a lack of power-though when taking off at a very VERY light throttle, I feel slight surging in my locomotion.  I believe I may have a slight intake manifold leak.  I had a low erratic idle at one time but checked for a leak with brake cleaner and found a small spot where the idle would jump when I sprayed (passenger side front of intake runner).  I gently tightened the bolt a bit and my idle has actually improved and I don't feel  that a gasket replacement is completely necessary, but will do so maybe when the weather warms up next season. 

My intent with this is to nip a problem in the bud before it leaves me somewhere.  I know the fuel pump life expectancy can be all over. If this behavior is of concern, I would like to know that so that I may play accordingly with driving the truck close to empty and setting aside some time to perform the swap.

Could this also be the Fuel Flow Control Module?

I found the P/N listed on AC Delco's site.

Fuel Pump Flow Control Module
Part Number:  20759945
Product Notes:
Fuel Pump Flow Control Module
Per Vehicle: 1; Years: 2009-2009

How would one of these act when on their way out?

What do you recommend that I do to make sure I don't waste my money?

I greatly appreciate your time and help!!

Anyone? 

Check to see how fast is it bleeding down.

Just turn off the motor and watch the needle go down/time it for 1 minute.

I started the truck and let it idle until the fuel pressure dropped to 43psi from ~60psi at startup.  This took about 10 seconds.

I let it run for about 30 seconds then shut it down.  Pressure did not change in a minute.  It only moved one psi down over the course of 5 minutes and that was very difficult to sense on the gauge. 

It looks good to me startup pressure should be 55-60 PSI  running pressure should be 43-45 and bleed down under 5 PSI in 1 minute is good.

You have a variable speed fuel pump so that may be what is happening unlike the older one that have a constant speed pump

So you're saying the erratic needle is ok?  It runs and drives well enough.  I was just confused by the needle movement.  I've only ever seen that with a pump on its way out.

The manual just gives the specs of the system. Maybe try it with another tester.

Here is how it was acting as I tested it as you suggested.

https://youtu.be/XoHGNgYPNEk

Looks fine to me, doing what it supposed to do.

THANKS!

That's all I wanted to know!