1986 4x4 ranger xl 2.9 timing/cooling issue's

[PINTHEUS]

when i bought this truck 23 months ago,the previous owner had done a tune up & mis-wired the ignition & she was running on 3 cylinders,not sure how long he ran it that way,i re-wired her & she ran much better with the exception of running much too warm,actually boiling if the heater wasn't turned on,several times the idle has jumped up much too high,then after a couple days return to somewhat normal speed,but noticeably faster than normal,,then a couple weeks later starts all over again,,now she's idling much faster,running very erratic & sometimes drags when starting like it's out of time,,I'M THINKING IT'S THE TIMING CHAIN & COMPONENTS FAILING DUE TO THE FACT I'VE REPLACED THE IDLE AIR CONTROL VALVE & THE THROTTLE POSITION SENSOR WITH ZERO CHANGE,,ANY HELP WOULD BE GREATLY APPRECIATED,,TYVM

 

[tmcalavy]

Or the radiator could be full of crud and need flushing/coring/replacing or the water pump could be getting ready to die. Check both before you dive into the timing chain...you'll have to go there anyway if it's the water pump.