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I have a 1990 4 cyl 5 speed trooper. It periodically has a "roaming" idle when in neutral or the clutch is engaged. Now that the warmer months are here it seems to be happening every time I drive. First of all, does this sound like an IAC problem? I realize it could be a number of things causing this and have already replaced the old vacuum hoses. Also, where exactly is the IAC valve located and what are some tips for cleaning/replacing said valve? I have video of the rough idle in progress if anyone is interested.
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derrickrwilson said:
I have a 1990 4 cyl 5 speed trooper. It periodically has a "roaming" idle when in neutral or the clutch is engaged. Now that the warmer months are here it seems to be happening every time I drive. First of all, does this sound like an IAC problem? I realize it could be a number of things causing this and have already replaced the old vacuum hoses. Also, where exactly is the IAC valve located and what are some tips for cleaning/replacing said valve? I have video of the rough idle in progress if anyone is interested.
Thanks
YOU DONT HAVE AN IDEL AIR CONTROL VLV IN THE TRUE SENSE , THE IDEL AIR IS A BYPASS ONLY , FIRST AND FOR MOST MAKE ABSOLUTELY THAT YOUR COOLING SYSTEM IS FULL, TURN THE HOT AIR CONTROL VLV ON THE DASH ALL THE WAY TO HOT REMOVE THYE RAD CAP AND FILL RIGHT TO THE TOP , DO THIS ON A COLD ENG OR SLIGHTLY WARM ENG ,NOT HOT, KEEPING ANTI/FREEZE UN TILL IT WILL NOT TAKE ANY MORE FILL IT SLOW TO GET ALL THE AIR OUT OF THE SYSTEM, AND THEN FILL THE OVER FLOW BOTTLE TO AT LEAST THE 3/4 MARK, MAKE SURE THE RAD CAP IS WORKING AND THEN SEE HOW IT DOES , IT SOUNDS LIKE YOU HAVE AN AIR BUBBLE FLOATING AROUND IN THE COOL ING SYS, AND EVERY TIME THE AIR POCKET PASSES THE ENG COOLANT TEMP SENSOR IT MAKES THE PCM THINK THE ENG IS HOT AND THE ENG SPEED WILL GO UP UN TILL THE COOLANT HITS THE SENSOR AGAIN AND THEN THE IDEL SPD WILL COME BACK DOWN AND IT CAN DO THIS FAIRLY RAPID , JERRY
 
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