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Old 04-30-2012, 06:59 AM   #1
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Ac

I was driving my cr yesterday and got a question. Is it normal for when you have your ac on and when u give it has the ac will almost quit blowing. I didn't know if this was normal or what. I can be cruising down the road and with my ac on high I can give it gas and it almost completely stops.
I am also fighting a slight high idle issue. Could this be linked somehow? Thanks
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Old 04-30-2012, 07:51 AM   #2
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Does your blower almost quit blowing. Do you have underdrive pulleys? Alternator size? First thing would be to knock out the idle issue
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Old 04-30-2012, 01:11 PM   #3
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Re: Ac

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Originally Posted by Travis B View Post
I was driving my cr yesterday and got a question. Is it normal for when you have your ac on and when u give it has the ac will almost quit blowing. I didn't know if this was normal or what. I can be cruising down the road and with my ac on high I can give it gas and it almost completely stops.
I am also fighting a slight high idle issue. Could this be linked somehow? Thanks
I really don't remember for 100% sure, but it seems like I read somewhere that at WOT the A/C is momentarily shut down to enable better acceleration for safer highway passing.


I do know that the ECU will kick the idle up a bit when the A/C comes on to compensate for the increased engine load to prevent the engine from stalling.
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Old 04-30-2012, 03:38 PM   #4
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It is normal. When you press hard on the gas, the computer interprets that you wanna move fast. This is called Wide Open Throttle (WOT). The ac compressor is shut off to give you back a few horsepower until you let up off the pedal.

---------- Post added at 03:38 PM ---------- Previous post was at 03:37 PM ----------

Quote:
Originally Posted by Travis B
I was driving my cr yesterday and got a question. Is it normal for when you have your ac on and when u give it has the ac will almost quit blowing. I didn't know if this was normal or what. I can be cruising down the road and with my ac on high I can give it gas and it almost completely stops.
I am also fighting a slight high idle issue. Could this be linked somehow? Thanks
Your high idle issue is not related to WOT or the AC. Check your TPS and reset the base timing.
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Old 04-30-2012, 03:44 PM   #5
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Re: Ac

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It is normal. When you press hard on the gas, the computer interprets that you wanna move fast. This is called Wide Open Throttle (WOT). The ac compressor is shut off to give you back a few horsepower until you let up off the pedal.

Your high idle issue is not related to WOT or the AC. Check your TPS and reset the base timing.
I thought that was the case, thanks for confirming it.


Since he said "slight" high idle, I figured he may be experiencing the small idle increase that should happen when the A/C kicks in.
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Old 04-30-2012, 07:01 PM   #6
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Re: Ac

Shutting off the AC compressor would not make the vents stop blowing air. If you peg the motor for 10-15 seconds you should not notice a difference in air temp really.


I don't have specific knowledge of the issue, but I'm guessing it is either the computer cutting off the fan(to reduce power required by the alt to power the fan), or the fan is vacuum controlled and when you peg the motor you are dropping the vacuum enough to cut off the fan. I seem to remember our HVAC system is vac controlled so I am going with the latter.

A vacuum leak could also be causing the higher idle, and adding to the fan cutting off when you go into higher RPM and lower vacuum production.
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Old 04-30-2012, 07:22 PM   #7
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My high idle is I can not get it any lower than about 1100 Roma. An when I stop at a stop light my rpms are about 1800 and then it takes about 45 seconds before it will for back to around 1100.
I already cleaned the maf and replaced the iac. I checked the tps voltage and set it to .98 volts and reset my idle. Any help would be awesome. I can't find a vac leak and I put a gauge on it. At the distribution block I have 17-18. Please help.
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Old 04-30-2012, 07:59 PM   #8
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I have 2 Ford trucks that do the same thing. My 05 Stang does it too.
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Old 04-30-2012, 08:38 PM   #9
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Re: Ac

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Originally Posted by Travis B View Post
My high idle is I can not get it any lower than about 1100 Roma. An when I stop at a stop light my rpms are about 1800 and then it takes about 45 seconds before it will for back to around 1100.
I already cleaned the maf and replaced the iac. I checked the tps voltage and set it to .98 volts and reset my idle. Any help would be awesome. I can't find a vac leak and I put a gauge on it. At the distribution block I have 17-18. Please help.
That is pretty good vacuum so it doesn't sound like a leak. I am leaning towards thinking it is just the vacuum dropping when the trottle opens, and thus the fan not receiving the signal and cuts off.

Might be someone with more HVAC knowledge than me who knows differently. But either way if that is your biggest concern on a 20ish year old vehicle, be happy.
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Old 04-30-2012, 09:26 PM   #10
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Re: Ac

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Originally Posted by Travis B View Post
My high idle is I can not get it any lower than about 1100 Roma. An when I stop at a stop light my rpms are about 1800 and then it takes about 45 seconds before it will for back to around 1100.
I already cleaned the maf and replaced the iac. I checked the tps voltage and set it to .98 volts and reset my idle. Any help would be awesome. I can't find a vac leak and I put a gauge on it. At the distribution block I have 17-18. Please help.
There are 2-3 articles in the Useful Info thread that will probably help you.
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