89 W250 360 engine,cool weather here,runs very rough on start up till warm almost seems to be running lean as it sputters like not enough fuel,new ignition temp sensor,map sensor and throttle position sensors.Took it to a mechanic and he seems to think ECM, It has a remanufactured mopar one on it with 4557391 part number that when i look it up comes back as a ECM for a 318. When i look up one for a 360 it shows like 3 different ones depending on the factory number which i dont have. Truck has a auto trans and was sold here in the midwest so that would rule out CA emissions type. Any ideas out there?