Got in my truck yesterday and at idle pressure was 5. Normally around 6 or 7. I thought maybe the cold had something to do with it since it was 19* at the time. BTW, the truck had been plugged in all night. It didn't get any better with the 15 mile drive to work, and the engine was up to full operating tempature. I left the truck sitting all day, and went to Nashville and back, got in and pressure was 4, temp was 16*.

I'm using the PS/MMM mix so I don't think it's gelling. Although I really don't want to because it's so darn cold out right now, I'm going to try changing the filter to see if it help's. I hope it's not the lift pump. Any idea's. Thank's

 

Yes, cold temperatures will decrease lift pump pressures by 1-2 PSI, more is the lift pump is getting wore out.

 

I also should have added that after a long drive (like twenty+ miles) the fuel pressure should come back up unless the temps are way below zero, then they can stay a little lower because there is not enough warm fuel going back to the fuel tank to off set the cold.

 

We had a really cold day here last year and while driving to work at 65 mph my FP was at 0 psi. Once the temps came up some it was back to it's normal 7-8 psi..

 

As the fuel thickens due to colder temps, it's going to show less pressure on teh gauge.

 

Ya, it was back to normal today. I was just freekin a little I guess.