2004 Chevrolet Venture Hard start

Just like when you go to a doctor, problems are often not diagnosed in one visit. When you run to a second and third mechanic because one didn't fix the car the first time, each one has to start over from the beginning. The other problem here is the guy who replaced a whole pile of parts. Defective parts should be diagnosed. If they are going to be replaced randomly, those that don't solve a problem should be removed and the old ones reinstalled.

You haven't included any details or information that would tell where to start, so my best advice is to stick with one mechanic who is a good diagnostician. The basics would include reading any diagnostic fault codes and measuring fuel pressure.