fjh

Trim code installed ? Each time? Can you do a Reflash on the ecu? Maybe something has gone sideways in there!?  The learning at limit thing is an odd statement Kinda  points to a programing thing in my mind! something is not making sense to the  ECU and it is shutting down number 4! But just me I'm a Gray engine Guy only Dabbled in MP stuff! 

You Might tri Reflash first before swapping or  getting the parts canon out again Stupider things have happened! we had ECUs do weird things before and it sounds heat related! from what you've been saying! 😡 and less labor intensive! cup of coffee and your Eyeballs is all that's entailed !🙄😁

By what all has been said here so far My Guess is EGR Cooler  or  turbo! what I Think  your seeing is exhaust gasses passed by the turbo seals and a small coolant leak there as well! Get an oil sample to start with ! And move on from there in my opinion! It gets worse as the load is applied There is a small amount of boost at idle for EGR purposes accounts for the steady wisp while idling! Oil sample then grab a straw! Pull the pan and pressure test over nite Problem with  MP is (for lack of a better term is the butrus plate)  it will make it hard to pin point where the coolant is coming from! Or Last resort  Get out the parts canon and start shooting parts at it starting with the cheap  EGR cooler  then the turbo  Don't recommend this   However...............  Note ! Usually ! If it were an EGR cooler there would be mass flow codes!

2 hours ago, steeler said:

Going to swap 3 and 4 and see if the miss goes with it. If it does, then I'm really bumfuzzled as to what is causing it. 

It isn't throwing an electrical code, just the learning at limit code. Really strange. I'll find out in the morning. 

Trim code installed ? Each time? Can you do a reflash on the ecu? Maybe something has gone sideways in there!?

6 hours ago, Trumbull_welding said:

Unfortunately already done under hood and in cab found one relay on the fire wall that was a little green but it was functioning and I swapped it with another to make sure 

Not sure you’re truck has this but there was a fuse panel to to the left of the clutch up the side that gave issues at a point epdm panel think it was called there was a tsb for it we replaced dozens of these panels and installed a bandaid boot around the panel 

44 minutes ago, BOBWhite said:

Yeah I'd say so. Bad parts counter service is almost entirely the fault of the company's system and training not the individual employee (although sometimes the guy might just be an a hole). And to be fair, getting yelled at by old farts all day ought to get old when its the system that's at fault.

Welcome to the site as well! Hope we can get a scoop as to what's going on behind the counter! 

Yup agree with that ! I found my self getting grumpy with our parts guys at time’s waiting for parts not taking in to consideration they get busy with customers and other folks! Go get the stuff you self and get shit for that ! They get pissed cause you did so! Happy to be away from it truthfully!Worse is when the bring in the wrong parts pretending they know what you need! Used to piss me off too!

1 hour ago, Joey Mack said:

yes,,  I remember,, I was just reminded on another thread..   wouldnt it be funny if he was the guy?   Karma???  I really dont hate him, just the crappy training..  

don’t lie you hate his guts! 😂

That was the key guy I was talking about in the other post 😂

yuo we’re hatin that parts dude!😃

7 minutes ago, Joey Mack said:

Mech,  I am quite sure as you read these posts, you shake your head and say  "what the hell it this crap"..  I find myself doing it, and I dont have as many years in, as you do..  I wish I did more with e-6 and older engines, as well as the trucks they were in, but I came around too late..  Jojo

You done good Joey! Not much changed just the addition of the drive by wire! The mechanical is the same! What I hated the most was the change to the bolt on cam gear! To sweat on! Dumb! Added insult to injury when having to do a cam job in the bush!

Do the swap! Definition of crazy apply here! Doing the same thing over and over! 
just sayin!

55 minutes ago, steeler said:

Replaced number 4 injector again ran great for 20 minutes and crapped out again. 

Mannn! Frustrating! Do the swap! Got to prove its electrical ! In my mind! Did you pin the plug ? Ignore the boss do the swap !

Just now, Joey Mack said:

He is a wealth of knowledge..  I pick on him at times to get a laugh..  

evil!

5 minutes ago, Joey Mack said:

now he's gonna ask what a VGT is..    

That’s fine! We’re all getting old! Buddy!

4 minutes ago, Joey Mack said:

I dont know the keyway guy..  should I ??   

Yup you bitched about him a week or two ago!
😂or maybe it was someone else!?

34 minutes ago, steeler said:

Replaced number 4 injector again ran great for 20 minutes and crapped out again. 

Mannn! Frustrating! Do the swap! Got to prove its electrical ! In my mind! Did you pin the plug ?

30 minutes ago, mechohaulic said:

sorry I have to ask !!WHY does a turbo have coolant going through it . ?? another topic shows how old and far behind I am.  need to find a Mack fleet close buy to catch up on things. 

Bro most all new vGT turbos have coolant to them think to keep the electrical crap cooler! Just my thought! I’ve been away two years now can’t imagine what has changed since I left! 

15 hours ago, Flynpenguin said:

Problem solved! Thanks to FJH I found the overflow valve on the back right side of the pump. Upon removal I discovered the o ring sealing the small end was bad. New o ring and now I build almost 20 psi with the hand pump.

However I suspect the spring may be weak as max pressure when running is only 40 psi. Spec is for 38-50psi.

Really surprised you got that out of there it’s usually a hammer and chisel show!

10 minutes ago, Trumbull_welding said:

Me either lol! Yes sir cleaned all the grounds with a scotch bright wheel and put back togather, battery’s are all good also checked the ground breaker on the firewall and cleaned the connections up there, no easily visible wiring issues without tearing into loom or pulling wiring out from behind eup’s. 

Is there and under hood fuse panel?  If so check it for green fusses ect maybe swap some relays around also you could have a bad relay!

2 hours ago, The Heinz said:

I like to believe I stand out from them however!

You likely do !!! Or you wouldn't be posting here!  Most guys don't Care!  Just a Job ! Keeping an open mind! Google stuff use what ever at your disposal to find stuff for people is key! Problem is its time consuming ! and you got folks coming at you from every direction mechanics customers ect ! Compounded by an antiquated poorly designed  computer system! Could be so easy if the Impact was set up correctly! Unfortunately they hired the wrong people with the wrong mindset to design it!

12 minutes ago, The Heinz said:

I GREATLY prefer Cummins over any other lookup. It actually makes sense and, like you said, actually has a functioning search. The only issue with Cummins is the Aftertreatment Device section, but that's because the OEM never sends them what device was installed at the factory, so Cummins lists all the available parts. At least Impact will show those parts, but Hino/Isuzu couldn't care less.  

Yup I'm not a Cummins lover by any means But they  Do have a common sense  approach to repair for the most part ! Unlike Volvo ! And if you have a Cummins in a Mack/volvo  you have the politics and finger pointing when shit goes wrong! Your problem , not My  problem bs with the customer caught in the middle! when it should be a TEAM effort! !

Hmm ! Not a guru on this ! You checked the block grounds and battery nite switch connections ?

5 minutes ago, The Heinz said:

Haha, I still respect my elders, I was raised that way. I can't imagine watching a prestigious brand like Mack get dragged into the dirt by a European truck maker. I agree that Impact can be really bad (nowhere near as bad as looking up UD parts, that company is an abomination), and the majority of parts guys are lost most of the time. I like to believe I stand out from them however! 

The problem with impact is the search or lack there of in my opinion! Cummins has it all over these guys in the repair and parts area!

14 minutes ago, The Heinz said:

Was going to suggest EGR cooler, but that apparently won't be a problem for you (Very smart of you). We've seen oil cooler/side cover failures before on both 11 and 13 liters, that could very well be your issue. I also wouldn't discount the possibility of the head gasket leaking, but we rarely see that at all. 

Its likley a MP7  ! As stated lots of places for this issue to happen even a turbo has coolant to it!  think you'll need to pull the pan to chase that one!

37 minutes ago, The Heinz said:

I don't exactly want to make it public, but I'm not super far from you. MP's and mDrives are absolutely my biggest money maker, that's for sure. 

Key is money maker! Hate em or not you still have work! And will do for quite awhile 🤣 ! don't forget All the manufacturers are facing the same issues Volvo/Mack are .I respect your statement also ! But  you need to step back in the line thou  some !  us old guys got seniority when it comes to the Volvo trash hatein ! They certainly trashed the parts system ! The old Mack parts system made parts guys look like heroes most of the time! Didn't need a book or computer to find stuff most of the time! Now you get the blank stare when you go to the parts counter! And its not all because the people are totally stupid! Note if you need to cross reference stuff get your self a PAI account There site works well for this if they have the part your looking for! 

10 hours ago, Flynpenguin said:

Problem solved! Thanks to FJH I found the overflow valve on the back right side of the pump. Upon removal I discovered the o ring sealing the small end was bad. New o ring and now I build almost 20 psi with the hand pump.

However I suspect the spring may be weak as max pressure when running is only 40 psi. Spec is for 38-50psi.

Stretch the spring a bit if you want ! 40 pounds is fine thou ! and If there is a tiny hole thru the center at the pointy end of that plunger solder it closed! I believe B IN B pulling is likely running a Robby bosch most racers like these pumps better! 30 - 40 psi  ok it will still pull fine at that stock! remember they have a high fuel demand when racing! pressure and flow is important there!