2006 Navigator

Good afternoon. I have a 2006 Lincoln Navigator and have a hard time filling the tank and P0455. Thought it was the tank vent solenoid, that wasn't it. the purge valve works. When I look at the tank fuel pressure it is .3 psi or 9" H2o. This has not moved. I make the assumption that the sensor is either open or shorted. I have scoured the web but I can not find any info on its location or if it actually exist ( i know it has to or it couldn't be under closed loop control) I assume the Expedition of 2005 or 2006 has to be the same. Does anybody know where this sensor is? perhaps it is located in the fuel pump / tank level sender?

Thanks for any help you can provide.
howardhhjr

Looking at the fuel rail, I wonder if it is combined, as there is another line connected coming from the tank. I was thinking it was a return line, bot there is no clamp on it so I dont think they would have a hp fuel pressure sensor with a return.

It looks like this may be a difference between my 2004 and a 2006. On a 2004 it's on top of the tank, requires tank removal to access. I can't find the pressure sensor for the 2006.

I'll offer this as possibility though. I fought with P0455 and filling issues on my daughters car for nearly 2yrs. It was hard to fill with fuel, just had to go crazy slow or 1/4gal at a time and wait for it to drain. It also kept blowing the tank pressure sensor out, 5-6 times over the 2yrs. The sensor tested fine, but I replaced it anyway after several instances of this. It never blew out again so I think that sensor was intermittently messing up.

Turned out the entire issue with filling was the little coated paper type seal that's inside the cap of fuel system cleaner had gotten into the filler neck. I had snaked the filler neck many times, but finally decided to try semi-flexible 1/4" water line and it hit something this time. That coated paper would flip up when trying to fill the tank and settle back down after the fuel drained down. I pulled the rubber hose off the filler neck and pushed the water line in and saw the little round plug. I was able to grab it with a pair of 90degree needle nose pliers and yank it out.

I appreciate the reply. I have owned this navigator since 2017. It has always given me issues filling. The charcoal canister is most likely toast. I would have changed it but it is obsolete. I actually bought active charcoal and am going to try to rebuild it. With the fuel pressure reading 9 in h2o I am not even sure the purge valve will open. I had the tank out previously to replace the fuel pump /sender. There is no sensor on the tank. Unless it is part of the fuel pump assembly. I tried following the lines but don't see any senser. The fuel rail sender looks like it may be also monitoring the main vac pressure as the hose is vonnected to the manifold vacuum. Still looking g

Since P0455 "should be" a fairly significant leak try smoke testing it. You can make or buy a smoke machine or make one. I really struggled to diagnose similar issues before I made my smoke machine. Now I hook it up and just look for the smoke. You may have 2 issues though.

A new replacement charcoal canister may not be available, but they often last a long time so maybe a used one is worth a shot if you think it's faulty. Mine has 293k miles on it.

Here's an example of a smoke machine that was posted by forum hotshot Hamfisted.

I'm making the Assumption being that the fuel tank pressure is at 9 in h2o that the vent is always open and the vapor solenoid to the vacuum is always closed. First thing I need to do is resolve the high fuel tank pressure. Then I can look for leaks. For sure 100% the tank vent stays open. I'm sure that the ECM is reporting back that there's a major leap because I can't draw a vacuum on it.

I just read a article here https://www.motor.com/magazine-summary/fords-evap-system-operation-testing/

About how the system operates. I need to find where the system measures the fuel tank pressure. If the system can validate the sensor & solinoid don't function. It will throw code and prevent the system from operating

OK I am fairly certain there are no massive leaks. I bypassed the evap control valve and can draw the tank into a vacuum. I pulled the vacuum line off while it was in a vacuum and plugged and 5 minutes later it was still in a negative. FYI I plugged the vent valve as it is open. During this test the fuel pressure remained at +9" h2o. Time to jack it back up and look for the tank pressure sensor