Hello Excursion lovers. I'm sorry if this is lengthy. I just needed to explain what's happening.

My Excursion was towed into the shop last Saturday because when I started it it ran REALLY rough. Like it was only running on 6 or fewer cylinders and almost choking for fuel. It had 1/4th of a tank of diesel. It got worse as it idled, speeding up then slowing down and eventually stopping. The week prior to this happening, it was in the shop for a vacuum pump replacement as well as a turbo vacuum hose reconnection. I picked it up on Wednesday and by Friday this new problem started. I did not drive it at all from the time I picked it up on Wednesday until Friday when these symptoms started. One of the other strange symptoms was that my remote failed to lock or unlock my doors. Also, when I tried to manually lock to doors the door lock would not depress. I have previously written posts about my PCM experience. But in brief, in 2021, one of the previous mechanics thought my Excursion's mechanical issue was a bad turbo (when in reality it was a bad PCM.) So they replaced the turbo but apparently did not install it correctly. My current mechanic noticed that a vacuum hose that should have been connected to my turbo was just dangling and he said my turbo would not have been operational as a result, so he connected it. I have heard nothing from them until today when I called and they informed me they are thus far unable to diagnose the issue.

Earlier this week, I emailed Jonathan with Diesel Tech of Chattanooga to enquire if this is PCM related (a separate post) and he said this issue is not PCM related but could be IDM or injector wiring and that the door locks were gem module controlled. None of which have anything to do with the PCM. So there's that.

Do any of you have thoughts, suggestions, or words of wisdom? I have been a member of this group since I bought my Excursion in 2007. In those years I have received GREAT advice from you and it has saved my sanity and my wallet. So, for years my excursion ran like a top and had no mechanical issues. Then In 2017 the PCM was thought to be bad and was replaced. Since then I have had intermittent problems (both PCM related and not) and between incompetent mechanics, bad diagnostics and stinking bad luck, these problems seem to be increasing in occurrence and are getting worse. Keep in mind, I am NO diesel expert, nor am I a mechanic. But I value the advice I have received from this group above the mechanics who have attempted to diagnose my Excursion's issues.

Thank you in advance.

 

Pickup foot in tank and/or dirty sock filters in there. For the locks it could be the door lock actuator. I've had them lock up to where the key would not turn the lock cylinder to lock or unlock the door.

 

Hi there. Thank you for that but what does that first part mean? Good idea on the door lock actuator!

 

Rain in your area? Leaking windshield? You have a GEM module piggybacked to the inside fuse box, behind the under steering wheel access panel. The windshields can leak, and water finds it's way to the GEM module causing various issues. Other things to investigate are your drivers valve cover 42 pin plug, wire harnesses under the valve covers, bad engine sensor plug ends (wire insulation degrades allowing the wires to touch)

 

The plastic fuel pickup on the end of the hard line that drops down into the tank are notorious for breaking...and when they do you'll run out of fuel at 1/4 tank. There are also some inline filter socks which get clogged up on that same pickup tube which will starve the fuel pump and/or engine for fuel. Most remove those sock filters and add a small see through filter...Baldwin BF7725, Napa Gold 3007, etc....just prior to the fuel filter between it and the hard line on the frame rail. The simple way to diagnose this is add at least 5 gallons of fuel to see if it clears up...it will still run like crap until all the air has purged out of the system.

If you are unable to physically move the door lock lever up or down on top of the door panel, it's a 99% chance your lock actuator is froze up...this has nothing to do with the GEM...

 

Thank you for the explanation! Makes very good sense now! I will mention all of this to the mechanic.

 

Interestingly, we have had rain recently but they also recently replaced my windshield and resealed it. So I'm thinking while a great suggestion, may not be the culprit. But worthy of investigation just the same! Thank you!