1989 Ford Bronco High RPM at Idle

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CHUCK PELLETIER
  • MEMBER
  • 1 POST
Engine Mechanical problem
1989 Ford Bronco V8 Four Wheel Drive Automatic 72.000 miles

I 've had my 1989 Bronco XLT, with 351 engine,as new ,and original owner. Lately when first cranking,the rpm goes up to about 3000.I have 72,000 original miles.Usually,after a couple of minutes,the rpm would come down to about 700,or some time a simple tap to the accelerator,would bring the rpm down.
Now,upon cranking ,the rpm stay at bout 3000,and go up,and down,by them self,never regulating back to a normal idle.
Took it to the Ford place,where I had a tune up,wires,plugs,rotor,and cap,and the idle throttle motor,and another throttle part was changed.
Ran ok for a couple of days,then started running sluggish,and dying,and then the throttle started running back up to about 3000 rpm at idle.
The Ford mechanic does not have anymore clues.Do you know what could be causing this problem.Truck is 20 years old ,been well maintained,and has always run great,until now.
Sep 22, 2009 at 4:23 AM
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JACOBANDNICKOLAS
  • ✓Experienced Mechanic
  • 110,246 POSTS
Has he checked closely for vacuum leaks? EGR?
Oct 23, 2009 at 5:17 AM
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