I own a 2003 Dodge 3500 V8 van. When I start the van it will not want to run properly for the first 3/4 of a mile only. After this it runs great. When I start the care, warm up or no warm up, & press on the gas it wants to slow down. I have to feather the gas just to keep it going. The van at this point does want to slow & stop. After 3/4 of a mile it runs perfect. I have driven the van to NY, South Decota & Georga on business without anything happening. 3 car places have no idea what is going on.
I’m thinking it’s a sensor of some sort. If there is no MIL, I’d look at the throttle position sensor. It often won’t cause the MIL to come on. It can be checked with an ohm meter.
If the engine has a cold start valve I would check that out for proper operation.