I have a Safari 1987, i changed my spark plugs and my car is starting to stall and cut off on me when im driving not sure what the problem is. I was told its the fuel pump but not sure!

gmc safari 1989

Problem occurred on Sunday 1/2/2011 the van was trying to stall at a light. Managed to get it home without stopping and when I pulled into the driveway it stalled out. Its been running rather rough and will not idle correctly ever since! Installed new tune up parts, plugs, wire, rotor,cap and then I pulled an error code 22 from the dash lights and replaced the TPS switch check engine light went away and no further fault code and van still running the same!

service engine code reset