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idle problems...

  • Thread starter Thread starter click
  • Start date Start date Sep 25, 2005
C

click

New Member
Nov 13, 2003
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Sep 25, 2005
#1
  • Sep 25, 2005
  • #1
One morning my idle shot up to about 2000, so the first thing i tried was to clean the IAC. So i did that and my car idles at about 1600-1900. When i turn the AC on the rpms drop about 300. I tried taking out that little rubber plug from the IAC and turning that allen wrench screw. I heard you close it fully and back it off one turn. It took me like 9 turns to fully close it. But, then i thought i would set my base idle. So i cleared the computer, then unplugged the IAC. When i started the car it still idled at like 1500 so i couldnt even set the base idle at that treaded rod. With the IAC unplugged shouldn't the car idle normally, but it would stall with the AC on right?

I don't know what else there is, because i spray carb cleaner everywhere hoping to find a vacuum leak...
 

R.J.

Member
Aug 20, 2003
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Warwick, Rhode Island
Sep 25, 2005
#2
  • Sep 25, 2005
  • #2
Try this:
'94-'95

Begin with a cold vehicle. The idea here is to get the car to a firm cold idle with enough air bleed capacity left in the idle circuit for IAC adjustment.

The idle stop should be set first. Back out the idle stop screw, away from the bell crank arm, until about 1/2 turn past the point where it no longer makes contact (blade fully closed). Using a 0.010" feeler gauge, tighten until gauge just drags between screw and bell crank arm. Remove feeler gauge. Tighten screw exactly 1 1/2 turns. If the screw is very loose, put a drop of loc-tite or silicone on it, so it doesn't work out of adjustment.

Now remove the connector to the Idle Air Controller (IAC) just on the other side of the throttle body. Start the car and allow vehicle to warm for 2 minutes. Give a small "blip" to let it settle. If it is having a hard time staying running you may have to get an assistant until you can get to the front of the car. Now open or close the air bleed screw (CCW opens) next to the IAC until the car idles at 575 to 600 rpm. For guys with aftermarket cams and an EEC tuner, you might want to idle a bit more briskly, say 650 to 675.

Obviously, this rpm range is by what the car and driver wants...IE, no set idle speed, whatever works for YOU.

Turn off the car. Now count the number of turns clockwise to close on the idle air bleed screw. If it falls between 1/2 and 2, it's okay, now reverse it out the same number of turns. Log the number somewhere in case you need it for the future. Reconnect the IAC. You are done.

If the air bleed screw is above 2 turns, it's a good idea to tighten the idle stop screw another 1/2 turn, and then repeat the idle setting. If it is below 1/2 turn, then loosen the idle stop screw by 1/4 to 1/2 a turn, and repeat the idle setting. Be sure to put another drop of silicone RTV on the stop screw if it was disturbed. Reconnect the IAC. You are done.
 
C

click

New Member
Nov 13, 2003
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Sep 25, 2005
#3
  • Sep 25, 2005
  • #3
thanks r.j. for all of that but sorry to say it didnt work. i can't get it below 1500 no matter what. At least i wont have any problems of stalling.
But i did what u said and the little allen wrench screw on the IAC no matter what i did from all the way closed to 10 turns all it did was make my idle higher. At fully closed my car idles at 1600 and as i loosen it i hear the engine rpms going up. And all of this is with the IAC, so i dont know what to try now. my friend says the IAC is broken but that doesnt make sense cause even with it disconnected it still idles high.
 

R.J.

Member
Aug 20, 2003
813
0
16
Warwick, Rhode Island
Sep 25, 2005
#4
  • Sep 25, 2005
  • #4
I'd have to say the IAC is bad. I know a guy who had a bad IAC and the car would idle at 2000. Couldn't even tell it was broken because all that made it bad was the fins inside could turn and there not supposed to.
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
34
129
Sep 25, 2005
#5
  • Sep 25, 2005
  • #5
If the idle sticks until you turn the key off and then turn it back on, that can be a sign of a bad TPS as well.

Good luck.
 

urban96

bubb rubb says:"woo woooooo"
Founding Member
Sep 24, 2002
3,464
1
69
Syracuse, NY
Sep 25, 2005
#6
  • Sep 25, 2005
  • #6
sounds like TPS or IAC... but most likely the IAC

try backing out the idle stop screw all the way but leave the IAC connected... it should still idle at around 625-650rpm(at least thats what mine does)

also do you have the little screw on the top open too much? the idle air bypass thing
 
C

click

New Member
Nov 13, 2003
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Sep 26, 2005
#7
  • Sep 26, 2005
  • #7
HISSIN are u say that im stop the car by turning the key and then when i put it back to on position it starts back up? Cause yesterday i shut off my car and i forgot about my windows so right after the car shut of i turned to key to on and the car came back on...
 

mo_dingo

20+ Year Stangneter
Aug 26, 2003
3,031
2
58
Tucson, AZ
Sep 26, 2005
#8
  • Sep 26, 2005
  • #8
Your IAC is likely stuck open. You need to replace it. Pep boys is the only place that sells the right one for our cars. It's made by borg-warner and it looks identical.
Scott
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
34
129
Sep 26, 2005
#9
  • Sep 26, 2005
  • #9
click said:
HISSIN are u say that im stop the car by turning the key and then when i put it back to on position it starts back up? Cause yesterday i shut off my car and i forgot about my windows so right after the car shut of i turned to key to on and the car came back on...
Click to expand...
Huh?

If someone has an idle that occasionally sticks and the only way to fix it is to simply shut the car off, wait a few seconds and then start it back up (where the idle is now magically normal), that is a sign of a bad TPS.
I am not sure that fits your issue at all.

Good luck.
 
C

click

New Member
Nov 13, 2003
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Sep 27, 2005
#10
  • Sep 27, 2005
  • #10
sorry hissin now i know what u mean, but i don't think thats it. The IAC may be stuck open. I was wondering though cause my friend with a camaro said that when camaros get high idle like they disconnected and reconnect the MAF or clean it. I disconnected it and the idle dropped to 700ish. And right when i reconnect the MAF it jumps up to 1900.
 
C

click

New Member
Nov 13, 2003
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Sep 30, 2005
#11
  • Sep 30, 2005
  • #11
bumpity bump bump
 

mo_dingo

20+ Year Stangneter
Aug 26, 2003
3,031
2
58
Tucson, AZ
Sep 30, 2005
#12
  • Sep 30, 2005
  • #12
click said:
bumpity bump bump
Click to expand...

R & I a new IAC valve and be done with it.
Scott
 
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