Tough Problem
 

I have a 98 MilleniaS with 110K. It has been in the shop now for 3 weeks and seems that no one can determine its problem. If you can crank it cold it will idle and run OK. As soon as you put some load on the engine, it begins to surge and stall and the engine will die our in a minute or two. If you rev the engine above 2500 rpm, it seems to run fine. They have tested catalytic converters, vacuum leaks, timing on camshafts?, two cylenoids that are locatednext to the firewall, bad gasoline, fuel pressure and a few other things.Anybodyhad this beforeor have any ideas?