steeler

Yes sir, trim codes programed every time, along with function parameter reset. I can reflash the ecu. I think I'm going to be headed that direction either way at this point.

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.

It's a new engine harness. That was replaced with all new injectors and cups in December.

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

Boss doesn't want to take the time to swap. I just now got back on the truck, been putting out other fires. So I've got another new injector and cup. But this cup has about 20 minutes of run time on it. I'm super tempted to slam the new injector in without changing the cup. I know that's a no no though lol

I haven't tried a swap, only because replacing number 4 injector fixed it the first time, if only for a test drive lol

Yes, compression perfect. Cylinder balance shows number 4 of the chart low, the rest are good.

Hopefully someone can offer some advise here. Short story is i originally replaced injectors and cups, along with engine harness. Truck ran for 700 miles then came in for injector 4 offset learning at minimum limit, and had a dead miss in #4. I replaced number 4 injector,truck ran great on test drive. Customer comes to pick up the truck and as soon as he starts it, dead miss in number 4 with the same offset code. Anybody run into this before? I've replaced hundreds of mp injectors without issue. I'm having a hard time believing I've got 2 bad injectors on the same hole.

Poisoning level is soot level. What is yours reading? Could be several things causing the increase. Bad differential pressure sensor, engine producing tool much soot etc..

It's a 2 valve. The valve cover is rounded, and has 3 mounting bolts on top of it vs a slanted valve cover with mounting bolts around the perimeter on the e7.

Looks like a like an e6 2 valve to me, by what I think I'm seeing with the valve cover.....

Id like to know as well. Ticks me off that mack doesn't use the low pressure sensor on the newer engines, just the aftertreatment fuel pressure. Actually the sensor is there on some, but nothing on the engine harness.

Idles at 900? Sounds like the infamous 6-4 fault. Any fault codes?

If there are 3 bolts holding the pump to block, it's an ambac, 4 studs with nuts would be the newer bosch.

I agree it sounds like could be fuel knock. Did you program the trim codes after new injectors? How about a learned data reset?

That's an ambac pump, correct? Our local pump shop we've used for years won't rebuild them anymore because of parts I assume. I'm sure you can find one somewhere though with enough searching. If it's an ambac, you don't need anything special to install it other than a rig to hold the gear while you torque the retaining nut, assuming the new pump comes without the gear installed...

That's good news. I'm sure the clogging is from the problem you already fixed. That explains the whacky temps you had.

I've had them almost completely face plugged and run fine power wise, just won't regen properly. Sometimes when that happens, you do a regen and the outlet temp skyrockets quickly from the excess soot basically "catching fire". You may not actually see anything at all, but the filter could still be clogged. I'd either have it and the doc checked, or replaced.

That outlet temp looks suspicious to me. Usually, not always, but usually when I see that the outlet temp is that much higher than the inlet I find the filter is clogged. Especially if it ran for awhile with the gunked up doser. So, the soot level will reset for you manually?

Oh HELL NO! I'd be super ticked off. As others have said, take it higher up. Still under warrantee you shouldn't have to pay a dime! The dealership I worked for I personally witnessed charging the customer, then filing warrantee for the repair and getting paid twice for the same job. There are some shady shops out there. I'm wondering if they missed something with the head, air compressor maybe? If they can't replace an egr cooler without everything leaking, I probably would find another dealer.

Those paint pen markings don't necessarily mean it's been into before. I've been seeing them on rockers that I know for a fact have never been touched. I've been seeing so many leaking cups lately that I've gotten really really lazy, to the point where if I don't see an obvious sign of the fuel system sucking air, I crack the fuel return at the head and if there is foamy fuel coming out, I go after cups. I'm sure it'll bite me in the ass at some point but the last 10 or so I've done, cups have been the culprit.

Nothing to see here! Please delete, I fixed the problem.

Thank you guys so much! This is the best place for reliable info, and I try to share a little knowledge here and there when I can. I've been to Chicago a few times for training, once back in 07 or 08 for the mp engines, but didn't ever end up digging into them deep on my own til several years later. By then I had pretty much forgotten most of what I learned lol. And it wasn't like the old days (90's) when I left with stacks of manuals! Mack sure didn't have a problem taking $1500 bucks for impact, but they sure aren't any help getting me the login info! Talked to 3 different people at support and got nowhere. I'll try them again Monday morning. Thanks again!

Thanks Joey, I can see it. I figured the washers were to align the head, but I want to make sure I wasn't missing something. No fear with the gear train, I've done several mp7s, but they are dowel so this thru me off a little. First head I've ever seen on any engine I've rebuilt that didn't have dowels! And that's pretty much every engine under the hood of a truck for the last 25 years lol. We purchased impact to get this info, but for whatever reason Mack hasn't sent the login info yet and I'd like to go ahead and get this head set. There is a rubber seal on these at the gear plate, not replaceable. It still seems intact, do you add silicone around it for good measure?

Since Mack apparently doesn't make actual repair manuals anymore... 😡 Looking for the torque spec for a 2019 mp8. Also I notice the 8 doesn't have dowel pins for the head?? Anything I should need to know about that? Or just slap some silicone on the timing plate, set the head, draw it back and torque it? Thanks for any help!