rpm hanging at 1200 with a/c on !

CHUXSVT

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My rpms hang when I come to a stop. Usually with the a/c on but also does it with it off. I did the block off plate mod. Didn't work. New Iac valve. Still hanging. Could a vac leak cause this.....
 

DVJ38

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Yup I was going to suggest the block off plate or gasket, or the hose restrictor. A vac leak could certainly cause a higher idle though, so that's where I'd start. Although it only idles high with the a/c on? Off it idles normally?
 

UncleSAm

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welcome to the club, ive replaced my vac lines, tps, iac, silencer hoses. next is the maf.
 

AZSN95SNAKE

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Mine only hangs when the AC is on and I come to a stop; but my rpms hang at 1800!! Only when the AC is on. Been getting about 15mpg lately because of this stupid issue. And I notice the battery power level goes pretty darn close to the low limit. Sucks doesn't it? Ha.
 

STAMPEDE3

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You do realize that it is supposed to do this?

It is only an issue when it hangs too high or to long.

Dashpot mode- raises idle when the clutch is pushed in and the VSS tells the ECM the car is still rolling over 3MPH.
This is to help braking and steering since it is a hydroboost system

A/C- idle is raised slightly to compensate for load from compressor whenever the compressore kicks on.

While it is annoying because most hang too high it still is normal and probably one of the most posted issues here.

PS, the block off plate is a band-aid fix if it works.
Clean/change IAC, check TPS voltage, clean MAF is all you can do.
After that you can have it tuned to be much better.
 

BraMas

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Mine only hangs when the AC is on and I come to a stop; but my rpms hang at 1800!! Only when the AC is on. Been getting about 15mpg lately because of this stupid issue. And I notice the battery power level goes pretty darn close to the low limit. Sucks doesn't it? Ha.
You are not getting 15mpg becasue of a hanging idle :bash:
 

F8L BYT

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I have found if you hit the throttle while its doing it and you are at a dead stop it will lower the rpm's where they should be
 

AZSN95SNAKE

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You are not getting 15mpg becasue of a hanging idle :bash:

Than you diagnose the problem. Been getting 17/18 mpg driving normally only getting on it 2x a tank (not a crazy driver) during the cooler months here. So that means no AC nor heater. Than the real summer starts kicking in so I'm using AC which is leaving a hanging idle up at 1800rpms and my mileage drops to 15mpg, what am I supposed to think? lol. Full tune up was done 3 months ago, so you can't blame that. No CEL codes no issues whatsoever besides a hanging idle at 1800rpms every time I stop any where with the AC on. Just using the scientific method lol.:shrug:

Didn't mean to sound like an a hole, because I reread that and realize I came off that way haha. Sorry. Oh and I do know about the maf, vacuum, and the other possibilities but it only happens with AC on so those kind of out of the question.
 
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