04 BEW Cold Start Issues, No Codes

First off, I'm sorry for making this thread. I've searched all over, and I'm stumped.

I have an 04 BEW with close to 300k, and it has a rough time starting in the cold. When I am able to plug it in, it starts and runs like a champ. When I'm not able to plug it in and the temps are in the high 30's-low 40's and lower, it feels like a cylinder or two didn't get warm and misfires for a little bit before it evens out. Sometimes, the car will stall and die, but fire back up fairly easily. I also get a decent amount of diesely smelling smoke when this happens.

I have the NGK 7v GP's, and software version 0282. I tested voltage at the harness with the coolant temp sensor unplugged, and I was getting 10.3v for about 2 seconds, and then around 5v for the rest of the time. My glow plugs tested at 1.1 to 1.2 Ohms. I have no codes thrown.

I'm kind of leaning towards harness, given the age and mileage of the vehicle, but I just wanted to check before I start throwing money at it.

I also noticed a small amount of diesel underneath the tandem pump when I unplugged the CTS. That needs to be changed but it wouldn't be the cause of the hard start, right? The car does have a little "shimmy" every few seconds at idle, and I'm thinking the leaky tandem pump is the cause of that.

If anyone could point me in the right direction, I'd appreciate it.

Thanks

Since it's an 04 model, this thread is a must read for you:
https://forums.tdiclub.com/showthread.php?t=328868

My car went in for the infamous glow plug recall, and for some time after I'd have rough hard to start when cold and especially when damp. I see you're in the PNW so similar maybe. I don't recall seeing code at first. Not sure if I had any scan tools at the time. Anyway, I lived with it for a year or more before finally seeing that thread. And like to drove my car through the front of the dealership after I realized- incomplete recall service.

It didn't need to be all that cold really, it never does here in FL.

But after I did this fix myself I never go to the dealer for service. Ever. Period. Full stop.

You could have a bleed-down leak in the fuel lines, air getting in at rest. Just turn key on and look around tandem pump and lines for cracks loose connection etc. But that would smooth out very quickly after starting anyway.

Hope it helps