Ok, I was talking with my dad about things today. The one thing he pointed out is that when we were ohming out the glow plugs by ohming the UVCH, we were getting unlimited ohms when we were using the ground in the harness. It wasn't until we used a chassis ground that we got the good readings, so we had assumed that we just weren't getting a good ground with the probe on the harness but it must have actually been that there is actually a grounding issue. Meaning there must be a wire off somewhere in the UVCH. So when I do get to pulling that valve cover, I expect that we are going to find something not plugged in. I will take pics.

 

A new set of duralast gold batterys and duralast starter all from autozone fixed my cold weather issues. But if its really cold and I dont have it plugged I in takes 2 or 3 cranks to get it statted with lots of smoke. Is that normal?

 

No, if your glow plug system is working properly, and you allow them to warm the cylinders up prior to actually cranking the engine over, there should not be hardly any smoke.

 

So after what I described, seems like I soon have a cold start issue. Any help or knowledge u can share to fix it.

 

That is in line with what I said earlier. A one volt drop doesn't sound right to me. If your ground is bad, that will cause this. Iirc there is no ground connection on the harness. I would find a wiring diagram for the engine. It will have the ground points on it.

 

Ah... I see what happened. That center pin in the harness is not ground for the glow plugs, the engine itself is the ground... you just need a hot wire coming to the top of each GP. I can already hear the next question from here: "Well... it the center pin is not a ground, what is it?" The center pin is 115-volt injector common... the IDM provides it and a ground signal to the active injector at the right time.

 

Read through this thread, there is a ton of information on cold start issues in it. If you come up with something specific to ask, we will be very happy to help.

So we still stand at pulling a valve cover and going from there. I will keep you "posted". We will get there. We are close, I can feel it.

 

And where is the ground for each GP? That's the engine heads that the GP's thread into, just a hot wire going to the top of each plug.

Going all the way back to page 1 where we were suspecting compression issues and thinking loose hardware from recently performed work (always a good place to start). Loose GP's would cause these issues. Advise pulling VC's and ohming each GP indivudually and checking for proper torquing. Take 5 seconds and check the injector and rocker arm hold down torques too since you're right there.

If the ohms check out, plug in and check at 9 pin using position 5. If it won't ohm out at the 9 pin and does at each GP, highly suspect UVCH issue.

 

Update. Had the drivers side valve cover off today and spoke with Rich(Tugly) for an hour and 23 minutes about a lot of things. Pulled the plug on a glow plug and checked voltage. It was good. Ohmed he GP harness again with the harness unhooked. Checked the GP relay for voltage and it was good. None of the injectors were prairie doggin', etc. We have come to the conclusion, at this point that we may be dealing with tired injectors.159,500 miles is a bit early but within the realm off possibility especially with me having been doing 8,000-9,000 mile oil change intervals for the last 90,000+ miles.The truck definitely runs great once it warms up, but if it is below 35 and it hasn't been plugged in for several hours, she ain't starting. I did an oil change and that got her to start when the weather was a little warmer and that is certainly an improvement, but obviously it isn't right. I am going to change over to synthetic oil and see if it helps. If it does, that will probably confirm our theory. If not, I am at an absolute total loss as to what is going on.tomorrow I am going to start her up and data log the warm up process for about 5 minutes or so and see if Rich can glean any info from that but this is where we stand currently.

 

BTW, while doing this work today, I found this-





This is where the intake attaches to the turbo. Anyone have an extra laying around?

 

2000ca250 got my old one.

 

Rich (Tugly), what numbers/data logging parameters do you think might show or point to a worn poppet valve(s)?



Jason, what where the results of the CCT test using A&E?

 

Here is some FYI for the thread. I believe this is what Tugly and HKusp are looking into next.

Here's the link to a great writeup by Dave at Swamps Diesel Performance:

http://www.swampsdiesel.com/files/7....Diagnostic.pdf

"***This normal wear on the poppet valve will USUALLY cause the truck to run rough UNTIL
THE ENGINE OIL WARMS UP*** as the thinner/hotter (high pressure) engine oil is much less
viscous, and can sufficiently pass through the worn poppet valve..while the colder/thick oil can
not sufficiently flow through the worn valve. "

 

You'll find that link (plus a few other useful ones) in my signature. For now, I think I'm experiencing one of my first sightings of the fast-approaching Start Hunting for Injector Time.

1. Truck dead, old dinos.
2. Remove old dinos, install new dinos.
3. Truck alive (barely).
4. Remove dinos, use fake stuff.
5. ????

#5 will give all of us an interesting answer, either way. I don't know of many scenarios where this much experimentation has taken place.

There is a no-start section in the AE class, and all the criteria is there... with graphs... including the graph from this problem. The data says it should run, but now we're just down to "Is the injector getting it done, or is oil the holdup?"

 

I'm so interested as to what you find out, as I am struggling with identical issues to your truck... Hope you resolve it soon so maybe we both can learn something!