petehenry

No did not do the update. Local mack said they don't kno anything about it and they couldn't help me on that. So how do I make them aware that there's something out there like that?

Thanks for all the help so far. A update on this., ok so I cleaned all grounds no difference. Changed intake temp sensor no difference. Than I swapped out the eup that had been throwing a code intermittently and that fixed the power cutout issue.. now my question is do these eups get weak and underfuel with age? Truck has 10k hours and it still seems underpowered my boost doesn't go above 25 and I don't have any smoke at all. And I put stage 1 injectors in when they was changed.

Ok so peddle switch was swapped out. No difference. Which wires are for throttle and which module do they go to?

The fuel pressure stays 70 psi when power drops. This truck is on a concrete pump so it gets a lot of idle. When operating it runs 1300 rpm but it never stumbles than only when driving.

JectAnd forgot to mention it runs rough a while when cold. That was reason we put injectors in but now same issue with new injectors.

I will swap a peddle out and see what that does. The only codes I have or had for last year was for one unit pump which comes and goes, it doesn't follow the problem. It has very little smoke so seems to be under fueled. Wouldn't any of those issues set codes tho?

Hello everyone. I have a 07 400 ai in a mr cabover . Vin# 1m2k197c27m039374. Am having serious power loss when petal to floor , feels like engine stumbles or derates to about half power only when petal is all or close to all way down. Max boost is 25 but goes to 0 when it stumbles. Fuel pressure is 60 to 75 when its pulling under load . Replaced boost pressure sensor. Replaced injectors and adjusted valves. Makes no difference with muffler off. Checked for boost leaks. Reflashed ecm. Throws no codes . Weight is 56k at all times. What do i check next? My dealer isn't much help. Didnt know anything about a 12b throttle update or even how to check if i had it installed. Next im thinking foot pettle, crank sensors. Or what do u guys think? Thanks.

Wheelbase not important . We can make it fit.

Low hours, 20k fronts, 46k rear

But why would shutting it off for 5 min fix it for the day? Than maybe next day it would run fine all day long.

we have 01 mr688s that randomly starts cutting out at all speeds than u shut it off for 5 min and after ghat runs fine. we had it to dealer and they replaced #6 unipump because off broken spring an test drove everything work great so they say it fixed but next day back ta same prob so i put a gauge on the fuel line an the pressure jumps all over the place from 55-85 psi but its never steady at any speed. any ideas?