Hello All,

We have discussed this truck many times but a few things have changed.

Since my next-to-last post here's what's changed:

1. A reman 6.0 diesel engine has been installed, thus eliminating the terrible oil heating problems I had. This engine has about 50,000 miles on it today. The engine was purchased from Jasper as a running, dyno tested unit. It came from them with ARP studs, Ford head gaskets, Ford oil cooler and a BPD EGR cooler.

2. The chassis has about 225,000 miles on it.

Now to the issue:

I am getting a "random cylinder misfire" and "Cylinder 6 misfire" code daily.

I have a Bully Dog GT tuner installed and erase the code daily only to have it come back.

Now here's the rub...while in the "Tow/haul" mode I do not get the code or codes and wonder if any of you electronics wizards have any insight into why this would be. My thought is that knowing what changes in Tow/haul may give us a good lead to what's happening.

I have never noticed even a momentary change in the truck when the misfire is detected...I've gone so far as to erase the code and let the truck idle until the code returned and have never felt even a momentary "hitch" in the idle.

We suspected it to be in the harness and did some checking but to no avail...then I towed my Jeep 1,400 miles last weekend (10/20 and 10/23 2016) and I noticed no codes when in Tow/haul mode...

I hope I've given you enough to consider...if you want to know anything, please ask and I'll gather the info.

Donnie

 

Bad injector, or harness issue. A FICM on the way out might do it too.

 

Donnie, I am having this exact issue with the exact codes. Did you ever find out the problem?