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I just bought an 00' excursion 4x4 with 7.3 diesel. My wife wanted one for a long time, and 5 kids later we finally had to get one. 10 days after the purchase she started running real bad and seems as though only 4 cylinders. I found this site while trying to diagnose the problem and couldn't believe how supportive the members are. I tried the .50 cent repair after some trouble shooting and found a melted UVCH on passenger side? I read dozens of post on this issue and never heard of one case like this. Can anyone make me smarter?
If its the center plug, it happens, usually from a loose connection. Do u have any pics you post to somewhere like photobucket and then put the link here?
Before u get the new harness, keep in mind that some members have reported issues with Dorman harness at some of the big box stores. It seems to be a quality issue on them putting the wires in the right place in the plug when they make the harness.
I'll get some photos when the sun comes back out. The burn mark or melted portion looks like a hot cigarette burn on the top of the UVCH toward the fairewall side. I was really hoping it just came loose but that's not my kinda luck!
Subscribing to see the pictures. Melted plastic usually comes from a short. Either a loose connection or a chaffed wire causing a short as it rubs against metal.
Melted plugs were more common on the earlier version 7.3 trucks, but it can happen to this model as well. Most of the time it's just a loose connection that caused it.
It's kind of hard to see due to the light in the photo, but I'm guessing you're going to need a new valve cover gasket. Unplug the connectors and pull it out. See if you don't have one or more burnt pins in the pass thru connector.
Did you have a check engine light with glow plug codes that showed up?
Time for a new valve cover gasket, and possibly inner GP/Injector harness. There's an updated version that gets rid of the inside connection on the valve cover, so it eliminates the need for a $.50 mod.
I never ran the codes, I know I should have but after reading how common the UVCH problem was, I was racing to fix it for .50 cents! I had already bought a new motorcraft inside harness plug deal. I didn't think to get the gasket kit, that's the newb in me. I'll update what happens by wed. All I can say is I sure am glad it isn't lifted what a chore to get comfy wrenching on these, the last time I wrenched it was on old cars with lots of room and access, time to man up!
I talked to my fleet manager at work today, we've always had PSD work trucks until this year they started buying F150's. Anyhow he said if it were him, he would change the GP's and the injector cups? while I have it opened up. The X has 225k and he says the injector cups start going around 250-300k. My question is, do I apply the if it ain't broke don't fix it logic? or the since I'm already in there logic?
...My question is, do I apply the if it ain't broke don't fix it logic? or the since I'm already in there logic?
Depends on how you look at it. These engines are kind of a pain in the a$$ to tear down to get to the injectors. (or at the very least, I hate doing them. TETO). It's your money, your time, and your truck.
The 7.3l is so much easier to get to the injectors and under the valve covers in a pickup platform vs the econoline. The heavier trucks/vans that are ran hard day in and day out will go through injector sleeves in that timeframe I agree. Typically they seem to last much longer in lighter not worked so hard applications. I would say fix your problem at hand with the new valve cover gasket and under valve cover gasket harness and take the other issues as they come if they ever do.
Glow plugs have a lot to do with the region and how often and hard they are used. North Dakota and Texas will go through glow plugs at different rates.
My injector cups have over 460,000 miles on them, so for the cups, I'm in the camp of if it ain't broke. For the glow plugs, I'm in the camp of, if they're getting old and the weather is nice outside, and you've got some time on your hands, then it's not a bad idea (avoid autolite plugs). Otherwise, if it's cold outside or your busy, and it ain't broke......