steeler

Got me baffled as well! 

I appreciate you fjh. I'm with you on the software. Just doesn't make any sense. 

I did tear all the rockers apart and checked everything. 

I know this engine brake solenoid is bad, has been bad for awhile. Somebody has unplugged the clutch switch, so it wouldn't throw a fault if they switched the engine brake on. Customer wasn't worried about fixing it, but.... It's getting fixed now lol

There is a function parameters reset, similar to the learned data reset. I did not run it long enough with the 1st test ecu to see if it threw the same code, But, I just pulled an ecu off of another 2015 truck in the shop, and the miss is still there with that one. 

Sooo.... For whatever reason it runs fine with a 2009 ecu, but not one with the correct year. 

I'm getting ready to put a new engine brake solenoid on it. No idea why that would cause only number 4 to miss, but I'm just about out of ideas. 

Sorry for the delay! Yes just came in today, hooked it up, and guess what! Still missing on 4!

Hooked test ecu back up, runs great. WTH. 

Surely there isn't anything parameter wise that got carried over to the new ecu causing this. I'm wishing now that I would have just programed the new ecu without transferring anything at all from the old one, but too late now. Once it's programmed, that's it, can't change anything other than software updates. 

Really scratching my head as to what would be different with these 2 ecus that could cause a miss on number 4.coming up empty in my head. 

Ok, swapped injectors, this time it was missing tight off the bat, same hole. 

I hooked up a test ecu, although from a 2009 truck, this one is a 2015. Ran great with teddy ecu, hooked up original one, still missing. So... Tried to reflash but tech tool won't allow it since the ecu already has a chassis ID programed, only new control units can be programmed. 

Software is up to date, so the only way to reinstall the software is to use the replace hardware function, which it won't let me do unless it's a clean ecu. 

This must be a new thing? I've programmed used ecus before without issue. 

Looks like I need a new ecu, but I think we are looking at the backorder game now. 

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. 

1 hour ago, Goddy454 said:

I will drop the filters and check them out anyhow but wouldn"t the truck lack power from the excessive back pressure if that was the case? And yes I have had no problem resetting the soot ratio.

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.