1991 Jeep Cherokee ENGINE IDLES HIGH, STALLS & APPEARS

HI, I HAVE AN INTRMITENT PROBLEM WHICH SEEMS TO BE GETTING WORSE. SOMETIMES IT RUNS FINE, OTHER TIMES THE IDLE WILL GO TO 1000 RPM AND NOT ANY LOWER, EVEN WHEN STOPPED, WHICH SEEEMS TO CAUSE THE ENGINE TO FLOOD OUT. IT WILL HESITATE OR STALL ON ACELERATION AND WILL NOT START UNLESS I HOLD THE PEDAL TO THE FLOOR AN CRANK IT OVER.
I HAVE REPLACED THE AIR IDLE CONTROL & AFTER I REPLACED THE TPS IT RAN FINE FOR ABOUT A WEEK. NOW IT HAS DIED AND WILL NOT START, SEEMS REALLY FLOODED.
I HAD A SIMILAR PROBLEM A YEAR AGO AND REPLACED THE CRANKSHAFT SENSOR.