the van starts ruff and then dies.Sometimes it starts and runs right for a few

Have the fuel pressure checked. Most injected vehicles need 45 to 60+ Psi's of pressure to run. Some vehicle will barely run with 20 to 30 psi's of pressure. You can see gas coming out,but you need to know the pressure when key is turned on and while it's running. Your pressure should be in the 50 psi range when idling.