CAT C15 /6NZ trouble continues

Sorry guys, i should be keeping this updated more often. In the past, anytime someone puts something on my post, a notification would pop up on my phone, but i havent received anything lately so i figured it was dormant.
Anyhow. Yes, i have more info to share.
Quite a lot of brokers have been calling and texting me about "having the same issue as i have". After talking to these fellas, some yes, most no, butm regardless, it is always good to hear from others with issues, as i can be the volunteer and middle man for others with issues and hopefully help some of yall.
Regarding my issue, unfortunately its still on going.
My letter to CAT president was answered in 3 days and i now have a district manager assisting me.
The new ECM CAT installed on my truck 3 weeks ago didnt help the problem at all.
Yesterday, i was at CAT where i was met by the district manager, a really nice guy with true interest in resolving my problem.
I pullred in the shop at CAT with my trailer hanging out the door while a very seasoned and knowledgeable tech decided to , first off, disconnect the "Air Dog" system and re plumb all fuel lines back to factory spec, so as to start from scratch. Regardless of the fact i had, over the past 18 months, installed a new fuel pressure regulator, and a few months thereafter, another again
(thinking that because fuel pressure in the head is so relyant on this easily installed device, that it just might be defective and because of it, i could be chasing my tail.
I left CAT with my loaded 5 axle trailer with 136,500 Lb on board and after a couple local rd turns, i jumped on it to merge onto the QEW hwy (100 klm / hr....62 MPH + - ) and the engine stuttered, popped / and chugged more than it did with the Air Dog installed and i sent a quick text to the district manager minutes later explaining this.
Well, i was already slated to return to CAT the next day (today) but wasnt able to due to the dedicated contract of a stamping plant i oversee.So, after i finish this info to yall, im going to live up to my word and email the district manager (who im sure is sleeping right now) to advise him as to my available time tomorrow so the tech back at CAT can install a fuel line with sight glass, which will poke outside my hood or somewhere within sight of my eyes when driving. This is plan "B" as scheduled. Ruling out (or in ) the possibility that air is in fact being fed somehow into the fuel stream into the head and of course, the injectors. Although this test has been repeated by many techs at 2 other shops in the past, it was always installed and test performed under idle while the truck was standing still. And as previously mentioned, new fuel lines, fuel pump, divertor valve, divider valve, fuel pressure regulator, primary fuel filter housing, both tanks were removed and alluminum fuel suction tubes checked for cracks at top knowing how fuel slosh can crack them quite easily, causing air to be sucked in. The hand primer pump was deleted and the fuel return line pressure blown out from the connection at the secondary fuel filter housing to the tanks. And the vent caps on both tanks checked for clarity of flow, and the taps (on top of each fuel tank) were checked to be sure they both were in fact, open.
So, tomorrow i go back to CAT and thereafter i will find some time to report on the findings or test results.
Have a good night guys. Till tomorrow. !!

 

I was at CAT today and the tech once again hooked up a sight glass to the fuel supply just prior to going in the head, and a 2nd sight glass just after the fuel exits the head, plus a seperate fuel pressure guage prior to the fuel entering the head, and a 2nd fuel pressure guage after the fuel exits the head. All 4 lines tied off at the passenger side mirror. He then connected onto my ECM port, sat inthepassenger seat with CAT ET program opened on his laptop, and the district manager sitting in the bunk.
I had it all going on !!
We then went for a 70 minute ride, unfortunately the 5 axle trailer in tow was empty, so it was difficult to load down the engine but we did manage to climb a few steep grades and get it to act up somewhat, but zero air passed through the sight glasses, fuel psi was 95 Lbs without fluctuations (good pressure).
So, at the end of our little trip, air in the fuel was ruled out, as was fuel pressure issues.
The strangest thing is , yesterday they disconnected my "Air Dog", which boosts fuel psi and removes air in the fuel. Yesterday when i left CAT with it disconnected, the engine acted up all that much more for the balance of the day, to the point where i was on the edge of turning around to go get it re-connected as i didnt know if i was going to make it back north where i load.
(i oversee a stamping plant, all the scrap loads via conveyor which i monitor on a app on my phone with cameras overhead both trailers. I dont have a choice if or when i want to load. When a trailer is full i have to hustle to swap it out, 24/7, 6 days/week. Ive never been late doing so, but the guy relieving me while i was on vacation 2 years ago was late by 12 minutes. The plant shut down, he got a $115,000.00 fine (we need special insurance for this gig, with $5000 deductible)
So, i have zero choice, i had to keep truckin to the plant, fartin / stumbling / popping all the way there, and all the way back.
Anyhow, NetFlix season #3 hopefully tomorrow, as i hope to return to CAT loaded trailer in tow so as to REALLY get this horse complaining so the tech can hear and feel it like the driver does.
Brake, clutch, fuel pedals, and steering column all at my hands and feet with the other ends of the formentioned firmly bolted or fixated at / beside or just behind the engine, surely brings to the driver the sound-surround feelings of this ongoing dilemna.
I will keep yall posted and up to speed.
Great thanks for your support and ruting me on !!
This will all one day, be behind me, i hope. And what a party it will be.. !!!
Good night...