Although I've used this forum for years I've always found a solution and never had to post so I registered just today. I reviewed a lot of prior posts and have not found this particular problem so adding a new thread.

I am the original owner of the vehicle described in my signature. The listed performance upgrades were made in anticipation of purchase of new, heavier fifth wheel trailer. Now, when towing this trailer for a few hours at highway speeds and then slowing down to navigate a town or backroads or whatever, the engine chugs and blows a bunch of black smoke. It's not hunting for gears as described in the TC lock/unlock threads. Rather, it feels like it is shifting prematurely into higher gears while speed and RPMs are low and then maybe the air/fuel mixture ratio is wrong somehow. In any event, by forcing a downshift to increase RPM and speed before allowing it to shift again I've been able to get through these short low-speed driving segments. I've never encountered this problem while engine and tranny are cold.

I always use either the #2 or #3 boost setting in the Edge tuner and when towing I also use the tow/haul mode. In the past I've not noticed any conflicts between Edge and tow/haul mode while towing, but that is one item I'm concerned about. I'm looking for feedback on this topic if anyone has any input.

I've checked the OBD II for codes and found none. And this is another topic I'm curious about because the non-continuous monitors in my OBDLink MX are providing no data. I'm not getting any Mode $06 diagnostic data from which I might be able to find failing/borderline ox sensors or other sensors.

Anyway, the main problem is the chugging while hot and towing and if necessary I can post the other 2 topics elsewhere if that's recommended.

Thanks in advance.

 

Sounds like its staying in a higher gear at to low of speed, try adjusting the TV cable.

 

Thanks for the quick feedback 00t444e. Can you provide any input as to why this occurs when motor and tranny are hot and not while they are cold?

I should also add that this truck has 173000 miles on it. It is due for tranny filter/fluid replacement, so might I expect a mechanic would be willing to perform band adjustments and TV cable adjustments at that time?.