Rpms fluctuate when im idling and i turn the air on

deftsound

Please ask me how much my supercharger cost

Apr 6, 2004

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39

Texas City TX

Nov 26, 2005

#1

• Nov 26, 2005

• #1

I noticed today, and am not sure if its normal, that if im stopped and idling and i turn the air on the rpms will drop for a second then go up to like 1000 then back to normal. When i go from defrost all the way over to max a/c the car actually almost dies before it goes to normal rpms. When im driving and i turn it on it doesnt do it. I assume this is normal because the car has to turn the extra pulley to power the air and when its at idle its at a low rpm thus less power is available...

Is this normal???

 

tomustang

Psychotic Member

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Jun 8, 2000

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McLean Hospital

Nov 27, 2005

#2

• Nov 27, 2005

• #2

yes it's normal

 

stangGT97

New Member

Dec 22, 2004

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Boston area, MA

Nov 27, 2005

#3

• Nov 27, 2005

• #3

tomustang said:

yes it's normal

Click to expand...

and annoying as hell

 

squares98

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Aug 20, 2004

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Orange,ca

Nov 27, 2005

#4

• Nov 27, 2005

• #4

I dont think that is normal, I hgad that problem(search mity2's thread), I replaced the IAC and bad pcv valve and the problem went away.

 

Orions98GT

New Member

Nov 20, 2004

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Overland Park, KS

Nov 27, 2005

#5

• Nov 27, 2005

• #5

When the ac compresser clutch engauges it pulls power from the crank, so the engine slows down, then speeds itself back up. This will also happen on defrost mode.

 

Twista

Active Member

May 7, 2004

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@ the z00 in chicago

Nov 27, 2005

#6

• Nov 27, 2005

• #6

yep its normal for the A/c to drag down the RPM's.

 

helty

some Ukrainian's enjoying a handjob via my credit

Mar 30, 2005

1,461

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Baltimore, MD

Nov 27, 2005

#7

• Nov 27, 2005

• #7

normal
free post

yeah, its normal

 

Mustang5L5

That is…until I whipped out my Bissell

Mod Dude

Feb 18, 2001

43,265

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224

Massachusetts

Nov 27, 2005

#8

• Nov 27, 2005

• #8

It's normal to a point. It should only drop the RPMs 50-100 RPM as the A/C compressor kicks on and off.

If you are dropping 200-500 RPM then something may be wrong.

 

triggz

Founding Member

May 15, 2002

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Gadsden, AL

Nov 27, 2005

#9

• Nov 27, 2005

• #9

If its dropping too much it's probably due to the IAC.
Do you have the 'copper cap' mod, or IAC restrictor plate?

 

Hunter-White

New Member

Oct 23, 2005

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Jonesboro Arkansas

Nov 27, 2005

#10

• Nov 27, 2005

• #10

Ha I noticed the other day that my rpms drop while I'm hit the power windows?!?! is that normal?

 

40th GT

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Apr 7, 2004

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Lawrenceville, GA

Nov 27, 2005

#11

• Nov 27, 2005

• #11

Hunter-White said:

Ha I noticed the other day that my rpms drop while I'm hit the power windows?!?! is that normal?

Click to expand...

Funny, I noticed it too. In fact, the RPM drops whenever I use a power accessory. (move the power seat back n forth, move windows up/down..)

To the thread starter: It's nothing to worry about. Mine drops down to almost 500 before returning to idle. (IAC modded)

 

69Rcode_Mach1

Active Member

Apr 20, 2004

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Salt Lake City, Utah

Nov 27, 2005

#12

• Nov 27, 2005

• #12

40th GT said:

Funny, I noticed it too. In fact, the RPM drops whenever I use a power accessory. (move the power seat back n forth, move windows up/down..)

To the thread starter: It's nothing to worry about. Mine drops down to almost 500 before returning to idle. (IAC modded)

Click to expand...

Sounds like your alternator is struggling to give it juice.

 

sgarlic

Founding Member

Apr 21, 2001

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Nov 27, 2005

#13

• Nov 27, 2005

• #13

Mine drops 200 RPM or so when I hit the A/C at first. Did it since I drove it off the lot..

 

Dave0803

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Mar 3, 2003

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Leonardtown, MD

Apr 12, 2006

#14

• Apr 12, 2006

• #14

yeah, mine drops when the cooling fans come on, power windows, and anything else that uses voltage. Mine has had a bad idle since the day I got it though. Do any of these things run smooth?

 

Cantslowdown

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Jun 20, 2004

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Mt.Home AR!

Apr 12, 2006

#15

• Apr 12, 2006

• #15

Mine drops with the A/C on but i havent run it in awhile I'll have to see how it works since its getting hot out side I tryed it awhile back but havent since..

 

Stang|ess

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Oct 18, 2003

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Hawaii

Apr 12, 2006

#16

• Apr 12, 2006

• #16

start your car with a cold engine, turn the ac on, and let it warm up. don't touch the throttle at all. after it reaches operating temps, turn it off and start her up. should help.