After warmup engine stalls during normal driving (1500-2500 RPM). Putting transmission is neutral engine restarts immediately and revvs fine (no problem 3000-4500 RPM). Engine pulls fine when accelerator pedal floored. No check engine light and mechanic says he can't find any codes or get it to stall. New gas, FI cleaner added, new air filter, new fuel filter, new plugs, new ignition wires, new crankshaft sensor. 104K easy miles. Thx.

 

I had the same problem on my 2000 buick LaSabre. I put a new idle control sensor on it and cleaned the fuel injectors. Problem solved.