Has anyone had a bad Motorcaft CM-4884 UVCH out of the box. I know what you're probably thinking, but these looked legit...had the sticky styrofoam piece covering the pins for protection, updated mid legs on the securing prongs to help keep plugged in,the correct part number on the plug in, along with made in Mexico. Everything seemed fine but it threw a P1316-P code and has a miss at idle. Ran a buzz test and then threw a P1274 code for injector #4. You can see more details of diagnoses here: https://www.ford-trucks.com/forums/1...pgrades-3.html in post #36. So basically everything looked good and functioned except for cylinder #4 wiring and/or plug. I have 2 sets...one for the Excursion and one for the F350...but debating on sending the bad one along with the other one back and just using my original UVCH for the F350.

 

I mean to get a doa product here and there isnt unusual.

Was it bought from a reputable source?

Is is completely open or just high resistance?

 

Yes, I agree it's understandable to get a bad one. I don't know how to check the actual harness for that injector plug, but will look into that tomorrow...

 

I read your post in your thread...I don't think it's odd to have a new faulty part from anyone, it happens on occasion. You just happened to be unlucky this time. Not a big deal, just have it replaced, problem solved.

If it were me, I would look into it and test it, but that's just me

 

To check the harness you'll need a multimeter set to check resistance. Then you can check resistance between the injector plug and the valve cover gasket connector. The center pin of the VCG and the pin for the black wire shouldn't read more than 0.2 ohms. Then the pin forward of the center pin should read 0.2 or less to the other contact if the injector plug for #4. Then if you check between the two wires it should read OL(over limit) infinite.

 

Yes, this is the way I checked it and knew it was an issue within the valve cover...valve cover pins on the inside, the harness (which is the problem), the injector solenoid, etc. But now I'm wanting to check the harness only while off the truck.

I have another one on the way which is supposed to be here tomorrow...just in time for the cold weather...

 

That procedure works regardless of the harness being installed or not. The pins match the locations from either side of the actual valve cover gasket.

 

Got it...I checked the culprit injector connector for both the black (ground) and blue (hot) and they both show .000, so the only thing I can think of is something loose inside the connector when plugged into the injector.

 

Hmm, any chance the pins didn't mate up right before or maybe they're damaged preventing a good connection?

 

Yeah, nothing is perfect so sometimes it happens. You mention the keys things that make it look legit but didn’t mention where you got it from

hopefully the next one works

 

That's the only thing I can think of because when I took the valve cover off I first unplugged #4 injector, changed the solenoid with another spare, plugged it back in, and ran a buzz test...same P2174 code shows up though the injector did have a stronger sounding buzz. So I unplugged everything again and inspected both sides of the valve cover gasket plug-in and everything looked good. Since I also had another spare valve cover gasket I installed that, hooked everything back up...with the culprit UVCH...and ran another buzz test, and same code pops back up. I have another new UVCH and valve cover gasket ready to go for my F350, so I grab it, hook everything back up and buzz test comes back clean. So #4 cylinder injector plug was plugged in several times, only to give me the same issue...code P2174.

Next I took everything back off and swapped the solenoids back, took the known good harness off the valve cover gasket for my F350 and installed it on the valve cover gasket for the Excursion, and hooked everything back up. Ran another buzz test, which came back clean...so I buckled everything back in place. I put too much value into that new Motorcraft UVCH being good and learned my lesson to check them with a buzz test before I install the valve cover back in place...along with the rest of everything else.

I did ohm the other UVCH waiting to go on my F350, but I will check them on the truck with a buzz test before buckling everything else up. I realize we are all human and make mistakes, which is how these UVCH are put together, and even the best product out there can have issues new out of the box every so often...

So thank you udsuth78 for teaching me something today. I've had that multimeter for a couple of years to check battery/alternator output, but didn't know exactly how to ohm wiring for resistance/condition.