Has anyone ever had their fuel pressure be somewhat erratic when the tank was low? Last night my pressure would read just fine when I was running through the gears but when I let off it would go to 5psi then to 10, 12, back to 5. Crazy. I had about 500 miles on the tank so I'm hoping that it was sucking a little air since it hasn't done it after I filled up. Am I thinking right?

 

Mine was doing the same thing so I just replaced it with the Walbro 392. You can see the thread I just started.

 

Hey Austin, did it have the same symtoms as mine. After I filled up everything seemed ok. My LP is fairly new(like that means anything) so I'm hoping that it was just getting a little air.

I'm leaving for Houston in the morning and I hope she doesn't lay down on me. But just in case, I have a spare campaign pump at the ready.

 

Exact same thing. Sometimes it would be at 15psi and drop suddenly to 2psi, It was worst at idle or cruising. Hope this helps. Enjoy the traffic I-45 was really backed up tonight headed N. through the Woodlands.

 

I'm going to be coming down 59 then I will cut over to 45 at Conroe to Rayford Crossing RV resort. Hopefully I'll miss most of the bad stuff.

 

I work about a mile from that RV park.

 

Try changing the fuel filter.

 

I'm not a believer in the fact that your fuel level could much to do with erratic pressure. I would more think your LP is getting ready to take a dump.
Unless you are actually intermittently sucking air, like as in out of fuel?............

 

I tried to replacing the fuel filter filling the tank all to no avail. It's just so erratic
sometimes you would have good pressure then nothing. I enjoyed driving the truck today without worrying about fuel pressure. The walbro pump makes the Fp guage the least important gauge in the truck.

 

My first lift pump was replaced by the dealer under warranty. This prompted me to get gauges. It acted funny like you are describing. I took it back several times knowing something was not right. They just kept telling me that the pressure was fine and not to worry about it. About a week before elk camp I ordered a new one. I was going with a bunch of ford guys and was not about to break down with them along. When I went to put the new one on I found the rubber hose going from the filter to the lift pump was kinked. The dealer did this when they replaced my first pump. Oh well now I have a spare. You might want to check this.
CJ

 

Well I drove 360 miles to Houston and maintained my pressure so it must have been low fuel. When I filled up, it took almost 29 gallons. I'll keep my fingers crossed.