Just replaced engine. Only used block, heads and distributor from new engine. After replacement it now runs terrible after it warms up. Replaced cam sensor, crank sensor IAC, MAP, TPS, coolant temp sensor and spark plugs. Has new injectors and 40psi fuel pressure. Runs "ok"(drivable but not great) till the thermostat opens and then starts to pop and fart and barely run. No codes present. Good fuel pressure. Timing marks are about 5 degree before TDC, Vacuum is a little low but not terrible.
Engine runs terrible after it warms up. on 1995 Dodge Ram 1500
replace o2 sensor called the updraft o2 sensor... its between the engine and the cat.