rough engine

Symptoms: Very rough starting, stumbles, very high idle even when engine is warm, poor gas mileage, engine stalls frequently, especially as you shift from park to reverse. Engine also stalls after cruising for 5-10 minutes and then stopping for a light/stop sign. Hard to restart, acts and smells like it is flooded. No check engine light.

Parts replaced within the last week:
1. new fuel filter
2. new egr valve
3. new IAC (idle air controller) valve
4. new distributor cap
5. new pcv valve
6. new rotor
7. new TBI fuel injector
8. new TPS (throttle position switch)
9. new fuel pressure regulator
10. new neutral safety switch

Any ideas? There seems to be no vacuum leaks.

Need more info on the truck and engine.