1999 Dodge Avenger Engine shuts off without any signs, tach

Just bought this used for my daughter, I detailed the engine, fluids, filters, extreme cleaning. Found a vacuum hose disconnected, reconnected and performance improved in accelleration and decellerations. Runs very good, though just dies during driving. Stopped, slow cruise, freeway, once at idle in driveway, all conditions. No error codes, no indication, no hesitations. Does require several minutes to fire up, crank rotates but either no spark or no fuel. All lights and radio fine, before, during, after. At least once a day, sometimes 3-4 in 30 minutes. All fluids fine, just stops running, sit for 5-10 minutes, then starts. During failure, rotation of crank but no sign of firing. Also no warning of trouble, just rpm to 0, wait ten, then fine again. The restart delay is a good indicator that heat or a reset is occurring.

Need advise.