I have been chasing random start-up issue that i think may be related to the AFS (Air Fuel Solenoid) on these emission equipped 6.8l machines.
and runs on LPG that would fault for Overcrank it also had a Check Engine alarm in the history that cleared itself which lead me to performing Problem 40 in manual 0J1195 Rev J.
After verifying proper gas pressure and verifying the O2 sensor functions properly I checked the resistance of the AFS as described in Test 113 and measured 35 ohms w/ a calibrated Fluke, manual says "approximately 27 ohms".
I witnessed the machine go into overcrank. After resetting the Nexus and attempting another start sequence, out of frustration I hit the on-demand regulator set-up and it fired right up. I had to do this three times a row. I then disconnected the vacuum line that leads from the AFS to the distribution block that connects each side of the regulators and haven't had an issue with start up or Check Engine since.
I wasn't able to call tech support due to the remote location of this machine. The parts diagram for this serial shows the AFS but doesn't list a part number.
My question is, has anyone had any experience with the AFS. I believe it is holding the regulators closed and preventing the engine from getting the proper gas flow to start.
Thanks in advance.