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Thread: Rough Idle only when the A/C is on Reply to Thread
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Topic Review (Newest First)
09-21-2015 01:03 AM
val3ntin K thank you.
09-21-2015 01:01 AM
sailor A vacuum leak would be a possible cause that matches the symptoms, tracing that down & repairing it might be the whole fix now.
09-21-2015 12:02 AM
val3ntin Yes i understand that but where the throttle is in the back of it it makes a sound like is leaking air or vacumm maybe this is the problem? There its the hose from the canistor purge valve that enters in the engine
09-20-2015 10:51 PM
amc49 It takes a period of time driving the car for the PCM to figure out you haven't fixed the problem, only wiped its' memory to then realize after a while the problem is still there.
09-20-2015 04:43 AM
val3ntin Hi i have a rough idle when ac is on and an when i shift to neutral some time my engine dies when the ac is on but only when the engine is warmed up i changed the iac valve and the air pressure sensonr on the manifold and stil nothind but when i deisconnect the battery for 5 min and putt it back the engine runs like new and the next day the problem comes back why? ?
01-16-2013 10:46 PM
amc49 Timing belt untouched, they're on the accessory belt.
01-16-2013 09:27 PM
PWGuy bump..
12-28-2012 12:11 PM
PWGuy
Quote:
Originally Posted by blakeclevenger View Post
So after changing the idler pulley, and the tensioner pulley, the problem is solved. They weren't horrible, but they clearly weren't operating smoothing like pulleys should. This had solved the rough idle issue for me when the A/C is on. My theory is that the car didn't have the power under idle in its old age to handle both the A/C and the crappy pulleys without getting bogged down. Also in this process I gave it a tune up (plug wires and plugs). The car runs significantly better and has no idle issue.

Lesson learned: Dont over think it and rule out the simple stuff. Hopefully this thread helps others. Thanks to everyone in the community that chimed in and offered their advice and experience.
To change both of these pulleys, did you have to remove the timing belt? Or are both of these pulleys on the accessory belt?
11-24-2012 11:47 PM
amc49 A lot of it is fan coming on while a/c is on. That fan really jerks idle down when motor is older. May be one reason why OEM fan is engineered to come on at a later temperature than many think normal. At one time before I put in diagnostic LEDs to show when low and high fan and a/c clutch itself came on, I thought that low fan was not coming on properly. I installed a standalone adjustable fan control set to come on at 210 and back off at 190. That thing switched fan on so much during the summer it became very bothersome at traffic lights, the engine always seemed to be shuddering from the fan kick-in. I installed the LEDs and defeated the add-on control and went back to OEM fan on temp of 230 degrees, the problem quickly became much less noticeable since fan was coming on far fewer times.
11-24-2012 02:07 PM
blakeclevenger So after changing the idler pulley, and the tensioner pulley, the problem is solved. They weren't horrible, but they clearly weren't operating smoothing like pulleys should. This had solved the rough idle issue for me when the A/C is on. My theory is that the car didn't have the power under idle in its old age to handle both the A/C and the crappy pulleys without getting bogged down. Also in this process I gave it a tune up (plug wires and plugs). The car runs significantly better and has no idle issue.

Lesson learned: Dont over think it and rule out the simple stuff. Hopefully this thread helps others. Thanks to everyone in the community that chimed in and offered their advice and experience.
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