Missing at startup, possibly until completely warmed up.

[Fordtoughranger]

I have searched the forums and I know there are several possibilities, and my best bet is probably to start by getting a code reader that will read the "DTC" codes, as it appears the Actron CP9145 must not be compatible with diesels or at least with the 7.3l.

The issue is on my parents 2000 F350 7.3l (all stock), was hooked to travel trailer, and had been idling for 5 to 10 min as I was finishing packing up the trailer to leave. Went to take off and as soon as under load the Service Engine Light would flash on and off with the accelerator. A noticeable miss and lack of power was present, pulled over after a few blocks and let the engine return to idle. Took off again and truck was running normal for a 50 mile drive.
Truck then sat for a few hours, and without trailer I made it a few blocks and the same issue returned until I could pull over and let it idle for a little bit.
Problem has seem to last a little longer the few times I had needed to drive it.

Fuel filter was replaced at first sign of the problem.
Engine oil level is good and appears clean for a diesel engine.

Curious what you guys might suggest as it seems like it is temperature related with engine temp, although I would think the truck would be fully warmed up after 5-10 mins of idling in 70-80 deg weather.

Like I said I will try and get a hold of a OBDII reader that reads codes on this engine, an Autoengenuity is what I see people are suggesting , unless someone has gotten an Actron CP9145 to pull codes and has a trick to it?

Sorry for the lengthy post, any advice is much apprecciated