302 erratic idle question.
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i ain't rite
Joined: Mar 2005
Posts: 65,481
Likes: 5,542
From: Marlboro Mental Hospital.
heater as in heat on floor.
all air comes out of the properly selected ducts. the very first thing i did was check for vacuum leaks with a can of carb cleaner. no change in idle at all on any lines sprayed.
all air comes out of the properly selected ducts. the very first thing i did was check for vacuum leaks with a can of carb cleaner. no change in idle at all on any lines sprayed.
Fleet Owner
Joined: Oct 2005
Posts: 20,786
Likes: 1,751
From: Kentucky
I still say there is a vacuum leak in the HVAC system......under the dash, not in the engine compartment. The link I posted has some photos of where the vacuum lines are routed.
Thread Starter
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i ain't rite
Joined: Mar 2005
Posts: 65,481
Likes: 5,542
From: Marlboro Mental Hospital.
but if it was a vacuum leak, it would revert to default through the defrost ducts at some point or another. this does not happen. that is how i know it is not a vacuum leak. at no time does the airflow ever go through the defrost ducts unless the control is set to defrost.
Fleet Owner
Joined: Oct 2005
Posts: 20,786
Likes: 1,751
From: Kentucky
Then I guess my hypothesis is wrong. But it is the only common denominator to your issue. According to your problem statement anytime you select a HVAC function the engine idle goes erratic. The HVAC functions are vacuum controlled, except for the blower motor speed.
Regardless, you do have a very odd problem to resolve. Perhaps it could be a whacky body ground?
Regardless, you do have a very odd problem to resolve. Perhaps it could be a whacky body ground?
Thread Starter
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i ain't rite
Joined: Mar 2005
Posts: 65,481
Likes: 5,542
From: Marlboro Mental Hospital.
that is my thinking, that the heater controls are causing one of the computer controlled sensors to skip a beat and freaks the computer out.
i am going to try the old wiggle the wire trick to see if i can get it to stop when the heat/ac is turned on.
i am going to try the old wiggle the wire trick to see if i can get it to stop when the heat/ac is turned on.
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