[TooManyToys]

When the fuel is cold, the thermal recirculation valve in the HFCM is open, so most return fuel from the secondary filter is looping in the HFCM. Once the fuel in the HFCM is warmer, the valve tightens up, and the return fuel mostly goes back to the tank, so the pump has to work a little harder. No surprise to see the reduced values of that magnitude you showed, ~3psi lower.

Debris in the tank is certainly a situation where the pressure could drop occasionally and then be fine. Pulling the tank down is not that hard as long as you use the HFCM to drain the fuel into a temporary container(s). That can be 5g pails from Home Depot (what I did) or a metal garbage can lined with two layers of heavy Home Depot bags (I've done that too).

I filmed pulling the tank down and opening it up a year ago.


Removing the tank.

 

[vitaminjoe]

Hey Jack,

Thanks so much for the link to the video. I've watched a few of your other videos and have always found them very thorough and well planned/executed. I must have missed your post of the tank removal procedure you used. I should have no problem following the same process.

Thanks again!

 

[TooManyToys]

Thanks for your comment.

Understandable that it was missed. I've been almost at a standstill for posting videos to my channel for over a year, and I don't start threads in forums anymore announcing I published a video. So many have said they didn't know of one I made.

As I showed in the video, when it comes time to refill the tank, you can flip the hoses added to the HFCM so the supply line is in the containers and the output to the normal tank filling port. It takes a while, but it beats spilling fuel everywhere.