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Old 06-16-2006, 02:52 PM   #1
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Default Dies with a/c and hot weather

Since the weather has been a lot warmer lately, I've started running the a/c from time to time. I've noticed that when it gets really hot out the car nearly stalls when I disengage the clutch. If I turn off the a/c it idles back perfectly. From time to time it will actually stall out.

Any ideas?
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Old 06-16-2006, 02:53 PM   #2
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a/c stepper motor.
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Old 06-19-2006, 10:23 AM   #3
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well now its getting worse. Not only does the car stall out from time to time. At idle it revs up to 2k and back down every 10 seconds or so and doesn't blow at cold air.

On top of that I started running hotter than normal yesterday in the 95+ temperature. Should the a/c fan run when it's that hot regardless of the a/c being on or not? Only having the one fan turning was having a huge effect on the temps, when I turned the a/c on it went closer to normal, although it never would reach more than halfway and the gauge.
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Old 06-19-2006, 12:01 PM   #4
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If the engine is cycling faster, it sound like your compressor is clicking in, but you may need a recharge.

What you could do to keep the second fan running is pull the wire off the top of the compressor clutch so that it doesn't kick in and turn on the A/C with the switch in the cockpit. Your cockpit fan switch needs to be on also(#1 to 4)
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Old 06-19-2006, 12:42 PM   #5
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I recharged it when I put in the replacement engine. It makes a weird vibration when it runs and the idle fluxation is not cool. I've always been used to it rising slightly to 1k and having vacuum around 18 hg/in, but risinging from 1k to 2k every 10 seconds or so and being at 15-14 hg/in makes me think its dying. I'm planning on replacing the cap, thermostat, and flushing the system to hopefully combat the high operating temps in the summer heat and I'll try disabling the a/c for now to run both fans and eventually replace the compressor.
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Old 06-19-2006, 01:13 PM   #6
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Idle Speed Control solenoid going bad, maybe?
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Old 06-19-2006, 01:17 PM   #7
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I thought about that but it runs 100% without the a/c. It idles perfectly and doesn't bounce what-so-ever
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Old 06-19-2006, 02:26 PM   #8
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try taking off the belt to the a/c compressor. maybe it's seizing up.
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Old 06-19-2006, 02:34 PM   #9
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good idea.
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Old 06-19-2006, 02:50 PM   #10
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Quote:
Originally Posted by braineack
I thought about that but it runs 100% without the a/c. It idles perfectly and doesn't bounce what-so-ever
Yup, guess that's not the problem
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Old 06-19-2006, 04:50 PM   #11
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There are several things that will cause that have not been mentioned. A simple fast solution is to crank up the idle speed a little. Idle is probably better set using a vacuum gauge rather than trying to read the tachometer.

Some of those symptoms cauld be caused by a sticking dashpot plunger. 30 seconds to check and 2 minutes if needing a small lube underneath the rubber protective boot. If the throttle plate is snapping shut too quickly will cause cause a stall or near stall. The dashpot also serves a damper to the throttle plate to keep it from fluttering when changes in airflow or intake manifold pressures change. ie. engine load.

Idle at even -18hg would indicate you have a fairly pronounced vacuum leak somewhere unless your altitude is over 4 thousand feet from sea level.
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Old 06-19-2006, 05:02 PM   #12
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Idle speed does not effect it. Dashpot works perfectly and has been greased resently.

Sorry I meant to say im in 18 hg/in when the a/c is on, and lately in the hot weather it goes all the way down to 14-15 hg/in or so. Normal operation with out the a/c running is a strong 20-21 hg/in
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Old 06-19-2006, 05:58 PM   #13
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I know how to fix it, Gut your A/C!
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Old 06-19-2006, 07:51 PM   #14
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I'd like to, but, I'm a *****.
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Old 06-19-2006, 11:05 PM   #15
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Could be the fast idle going bad. What is the AFR on fuel trim? 18hg though means vacuum leak.
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