1986 GMC Safari Engine Stalls

I have had problems with this van since the day I bought it about a year ago. It sometimes will run great. But most of the time if you take your foot off the gas it will die (sometimes even while driving down the road with foot on the gas!) It will surge as you are driving, I smell some gas, but it kinda feels like its flooded. I have taken the throttle body off and cleaned it out very well, replaced the EGR valve, and also cleaned out the intake manifold. The service engine light comes on but the code scanner says no codes found. Sometimes the light will come on, sometimes it wont. Is my computer going bad, could it be a map/maf sensor, or am I just insane for wanting this van in good condition to run like a 4.3 should?