Dalton1

McFarland spring is still across the street, they usually seem pretty busy. Doesn't sound familiar but I'll ask about him next time I'm up there.

It's not old to me either, newest truck I've ever owned, I bought because I wanted the newest truck I could get with a true Mack engine. They work on them but last time I was there they only had one guy that knew anything at all about the grey engines. I think the pump shop your talking about was converted to the Hino sales office unfortunately.

I wish you were still working there!! I just pulled the nozzle, visual looked ok, swapped it with #5 and the problem moved to #5 so I guess I got a bad nozzle, thought I'd get more than 40 miles out of it.

I'm doing the work myself, I usually do everything but this one is challenging me. There's just O'Connors in Portland but from what I understand the don't do much with the old mack engines like mine anymore. I don't know anyone local that works on them.

Oil level doesn't seem to be rising but it hasn't run much either, just a few minutes. I'll pull the nozzle in the morning.

I'll give that a shot next, there's no smoke at all so I wouldn't think it would be a Cracked or failed nozzle. Here's that video if it's any help https://youtube.com/shorts/fkKcnWAUbiw?feature=share

Finally got the ecu swapped out, made no change unfortunately. When I cracked the #6 cylinder injector line it is a fairly steady flow of fuel and seems very aerated. Even makes small bubbles, no matter how much I bleed it. Any other ideas? as I said previously it does this same thing with a known good EUP. Any chance the nozzle could cause this somehow? I don't see how but they are new so it's possible I got a bad one or installed it incorrectly. I took a video of the way the fuel comes out but not sure how to upload it, I'll work on that.

Thanks everyone, I will try that next and update with results.

Maybe I'll give that a shot next. I find it odd my scanner won't preform cylinder deactivation tests on any cylinder, always work before on that truck, makes me think there might be an issue in the ECU. I did check the lobe and lifter both look perfect.

There's no smoke at all, the valve train appears to be ok and is in adjustment. Engine brake still works high and low so I don't think that stuck on. No rag in the intake but I would have been happy to find one! Tried swap wires on eup and cleaned ecu connectors with no change. I have access to a twin truck, would it be worth swapping the ecu? Or would it not communicate properly?

I did swap out the 5 and 6 injector, problem stayed with cylinder 6, I'll clean up the pins on the ecu and connector, is there a best way to do that? Electrical contact cleaner? Thank you for the help, that page out of the manual is helpful.

I'll give it a shot, yes valve were done by the book, problem came on very suddenly. Like that cylinder just shut off.

Pins aren't perfect but don't look to corroded, they have dielectric grease on them.

No codes at all unless I jump out one of the EUPs it'll throw low voltage codes to all 6 EUPs, is that normal? I recently went through all the grounds on that TSB about the 9-2 code and it solved that issue.

To update, I checked all wiring going to #6 EUP, pins on the ecm and swapped EUP with another cylinder to make sure I didn't get a defective one, still no change.

I have an 07 CV713 with a AI400, I'm having trouble with a missfire on cylinder #6, for some background information I've had this #6 EUP break the hold down bolts twice in the past, about 20k ago and 5k miles ago. Both times eup was replaced as well as new bolts. Most recently I replaced all the nozzles. As well as re o-ringed all EUPs with new bolts. The truck ran great for about 40 miles, better than before with the new injectors. But then it started skipping, I narrowed it down to #6 cylinder, it was just streaming fuel out with the injector line when cracked instead of pulsing like 1-5 and no change in idle. So I put yet another new EUP and bolts as well as inspected lifter roller and cam which both look perfect. I also found some damage wires to the EUP (from when the bolts broke) and repaired that. I still have the same symptoms and am at a loss, there is no fault codes. Also when I jump the terminals on any EUP to test that cylinder the engine shuts right off instead of cutting just that cylinder. Also will throw codes for a short on all 6 EUPs, not sure if that is normal when jumping them. Any help would be greatly appreciated!!

Mine was almost done on the side of the road too, of course had the plow, wing and 12 yards of sand on at the bottom of a hill when it let go, luckily a guy with a shop up the road bailed me out and dragged it there with his backhoe. Good to know thanks, oil change will definitely get done, unfortunately I changed it not long ago and of course this truck has the 52 quart pan. Anyone ever tried to drill it out and make a 7/16 or m12 bolt work? Seems like there's plenty of meat on the block for that. I'd love to find a way where I don't have to worry about it, not totally confident in the helicoil.

Anyone have any ideas on how to help prevent this from happening again? Would putting heat wrap on the down pipe or turbo be worth it to help keep heat off of the EUPs?

I had a new one on the shelf already that already had a core applied to it, guess I'll just use this one as a core towards the next.

Thanks for all the advice, got it back together, had to helicoil one hole, the other seemed ok. Used new bolts and put a new EUP in. Is the EUP that blew out worth saving or just a core now? Looks ok but wasn't sure so i threw a new one in. Only has 15k on it.

I will check the threads when I get the bolts out, if they're loose what would you recommend? Helicoil?

Pulled the roller and it looks ok to me, what do you think?

I have a 07 CV713 with an AI400 and about 15k miles ago i had the number 6 (rear most) EUP get pushed out of the block breaking both bolts holding it in flush with the block. Got both bolts out installed a new EUP and hardware from mack and torqued to spec. Then tonight had the exact same thing happen on the same cylinder again. Anyone have any idea what would cause this to happen? Haven't had issues with any of the other cylinders, all the heat shields are in place.

I forgot about that, most of the snow fighter trucks had an air switch on the dash to flip a shutter in the air cleaner to pull air from under the hood though a 2nd tube in sub zero weather, my '81 RD had this option and even my '07 Granite still does. Pretty sure those setups only used one filter though not 2 like the tip turbine.

The second tube went to the tip turbine on certain engines, the 300+ used them and I believe a few others as well. It's a sort of blower that is powered by a bleed of compressed air from the turbo to blow cool air over an engine mounted intercooler.