Hi Y'all. Been experiencing an issue with my 92 5.2 D150 where at start up it runs fine for about a half mile or so and then seems to start wanting to buck and back fire. My thoughts are it is likely running in one loop when it is first started and then when it changes to some other mode or loop, which may take outside inputs it starts acting crazy.

I know for some shops early 90's Dodges are not easy to diagnose as they are not OBDII and I think required a special scan tool as well. Thought maybe some of my friends here on Moparts might be able to help point me in the right direction.

To save time, here is a list of things changed within the last couple years. Temp sensor, IAC, plugs, wires, cap rotor, fuel filter, MAF or what it MAP, coil. I also had the plenum gasket replaced a while back.

Also to add it does not seem to do this in warm weather.
Any thoughts are what could be causing the truck to act like this or what direction I should be investigating further. Any feedback is certainly appreciated.

I've seen upstream O2 sensors do that. They are ignored while the truck is in warm up.

Had same thing in my 92 and 93 in the past, the 93 twice now over the years, all 3 times was a bad crankshaft sensor, minor crack in the housing, not easy to change but fixed mine all 3 times(behind right cylinder head).

Funny I was thinking about crankshaft sensor as well as a possible culprit. These 90s vehicles are tough cause they don't like to through codes and do things seemingly at random.

I have a 99 CTD with 227k miles and I just install crank trigger #3

Early are OBD1.Just turn key on and off IIRC 3 times and read the flashes fro check engine for codes.At least a start.Almost any decent shop should have an adapter for OBD1.It could be the O2 as Ive seen some jeeps do what you describe.I know some V6s had bad dist gears.they would wear and cause problems.Rocky