Well the starter was rebuilt less than 2 years ago and I haven't had any trouble with it. I was having trouble getting forscan to hook up but it finally did. However that was after cranking the truck.

I forgot to check the hpo level but I do need to do that. Again, I've always ran 15w-40 because I've never had one issue with it starting cold, while it might help, it certainly isnt the problem I need to get the icp while its cranking. This video was it plugged in for about 3.5 hours, temp around 18 degrees. It starts half decent but not great and also has that slight "miss" until it warms up. I drove it for awhile and it seems to drive just fine. I'll get an icp reading (hopefully) with it cranking, also check the oil lever at the reservoir and go from there.

https://youtu.be/yd1H9S7f3rA

 

+1. I was stunned at how much of a difference just installing new OEM battery harnesses made in the speed the engine rolls over. I was thinking the batteries needed replacing again, as the P.O. was changing them every 3-6 months (under warranty). I haven't had a problem since changing to the new harnesses, same batteries. I get some smoke on startup when it's below 40*, but with 250k, original injectors, 15w-40, and two known bad glow plugs, that's probaby to be expected.

 

That probably is a bad injector. It "wakes up" as the oil warms and runs nearly normally when hot. That can be lived with for awhile. Doing buzz test with ForScan might help pinpoint which it is but realistically if you intend to keep the truck you'll want to have them all replaced at the same time. You can still chase the starting problem though since that is a bit more immediate concern. My truck has a bad injector too but still cold starts fine no plug in or anything.

 

I ran a buzz test but to me, I couldnt tell a difference. My fear is that theres 2 issues. I'm hoping to either confirm, or eliminate a hpo issue. The cutting out then warm up I agree would probably sounds like an injector, but it shouldnt take 3 cranks (with it unplugged) to come to life (I wouldn't think)

 

If it was a poppet clearance problem, you would have definitely heard the difference in the buzz test unless they were all bad.

I agree on the batteries and starter. Replaced my starter a couple of months ago and noticed a difference in the cranking speed, then I replaced both batteries when my truck would no longer start. Wow, what a difference those 850 CCA batteries made. Single digit temperatures, one cycle of the glow plugs and she fires right off.

 

I dont think the cranking speed has really anything to do with it. When I'm jumping it, it spins over like its 70 degress.. heres 2 new videos. Truck was plugged in for roughly an hour. I dont see any issue with icp, it seems to be working as it should. Also, I check the oil level in the reservoir and it was right around the 3/4-1 inch like it should be
https://youtu.be/JNzFWdpUR3M

second video is the second attempt at cranking. I can tell when it starts that there is definitely a weak injector or 2 but I dont think that is the issue with starting. Every time I test the relay, it is turning on like it should (I had problems with that as previously stated). It's almost as if the relay doesnt turn on sometimes if its glow plug related

https://youtu.be/yxt6dyMtSg8

 

The buzz test won't tell you anything if they are all equally worn unless you do this every day and know exactly what they should all sound like. One or two may be worse than the rest but at that mileage; If they are original, they are likely shot. Sounds exactly the same as my situation. I did everything you have done trying to rule it all out but ended up biting that $2500 bullet for injectors and new tunes. Never had a starting problem again.

Another good test would be to switch to 5w40. This will make any truck fire up a little better and run smoother cold, but if your injectors or HPOP are suspect this will make a very pronounced difference, you'll get much better cold starts. My truck would start as low as 20-25F with 5w40, on 15w40 it wouldn't start at 40F outside unless plugged in.

 

Did you do the buzz test cold or with the block heater running? If it was warmed up the buzz wouldn't tell you what's happening when cold.

When it starts and is running rough is it smoking white? If so probably glow plugs, if not probably injectors. Measure the injector armature clearances or just switch to 5-40 and see if the problem goes away. With 300+k miles the injectors are probably worn enough to cause some cold start issues. A cold buzz test 'should' expose worn injectors, but it relies on you knowing what to listen for.

Mine has worn injectors and 5-40 made a huge difference. With 15-40 it had to be at least in the 70s, maybe 80 to get a good start. With 5-40 it'll start down to about 60 pretty well. Plugging it in for 40 minutes is often enough to get the injectors firing right away after a 40-50 degree night. Someday I'll get around to them.

 

The buzz test was cold. And also I would say it was a combo, pretty white at first then after 30 secs or so was more clear/blueish until it fully went away

 

ICP and IPR looked okay. Take a video of a cold buzz test. The starter and batteries sound fine. My original log starter was toast and would turn slower than that even with strong batteries but I could still get enough spin out of it to cold start the motor on the first try 99% of the time. (Put a Denso 4kW in a few months ago)

 

Maybe get some of that new AMSOIL 0W40 and see what happens.

 

Please clarify how buzz test was conducted. Test is run KOEO and should take maybe 15 seconds - should not produce any smoke as the engine is not turning over. It is an electrical test of injector solenoid system and variance of sound indicates weak response of either solenoid, wiring, or poppets.

Running a buzz test may allow residual oil pressure to allow residual fuel rail pressure to inject a small amount of fuel.

My best guess is worn injectors - measure the solenoid armature clearance and if out of spec spring for NEW Alliant injectors or shim what you have to spec.

 

White smoke so it's not injectors, you're getting unburnt fuel. Glow plugs or maybe low compression, fuel is being injected and not burnt.

 

I can post a video of the buzz test again on the cold engine. I was answering 2 questions previously as to the smoke. The engine was not running and I just followed the steps in forscan. I would like to put a light on the relay to verify that the relay is staying on everytime for plenty enough time. I'm just confused as how last year the truck was great and all the sudden it's got to this in one year and not really many more miles. I understand things wear out but I wouldn't expect all the sudden.

 

You have to remember, anything created, designed or built by humans can and does fail.

Also, that is how things break right? One day they are good to go and functioning properly, the next day they are not. That is how it goes and will continue to go, for everything.

Keep at it, you will get it sorted.