IAC question
Thread Starter
Racer
Joined: Jan 2010
Posts: 347
Likes: 12
From: Deltona FL
IAC question
I am having problems with the motor surging when at a idle... I have been reading posts all morning and I am going to check for vacuum leaks and the IAC tonight.
My question is can the IAC be removed and cleaned w/o removing the TB? 1986 stock
My question is can the IAC be removed and cleaned w/o removing the TB? 1986 stock
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 412
From: WV
Yes and no. Yes the IAC can be taken out and cleaned but to do it right the whole unit needs to be cleaned. There are passages that the air flows through that will have gunk in them that should be cleaned with carb or TB cleaner, and taking off the TB will also allow you to clean the carbon off the back of the TB and out of the plenum..You will also need to replace the 3 gaskets for the TB and the IAC gasket.Just clean everything up and put it back together, only takes about a hour to do..WW
Last edited by WW7; Jan 11, 2010 at 02:06 PM.
Burning Brakes
Joined: Oct 2009
Posts: 773
Likes: 2
From: Minneapolis MN
Yes and no. Yes the IAC can be taken out and cleaned but to do it right the whole unit needs to be cleaned. There are passages that the air flows through that will have gunk in them that should be cleaned with carb or TB cleaner, and taking off the TB will also allow you to clean the carbon off the back of the TB and out of the plenum..You will also need to replace the 3 gaskets for the TB and the IAC gasket.Just clean everything up and put it back together, only takes about a hour to do..WW
If you do this just replace IAC if you do not know the age or last time it was replaced.I don't want to sound like a broken record but our cars are getting old & if parts are old,possibly original & suspect just replace as these parts may be near end of there useful life.I'm not saying replace every part but if part is original & suspect-replace it
Burning Brakes
Joined: Aug 2001
Posts: 1,146
Likes: 9
From: Troy Ohio
If you do this just replace IAC if you do not know the age or last time it was replaced.I don't want to sound like a broken record but our cars are getting old & if parts are old,possibly original & suspect just replace as these parts may be near end of there useful life.I'm not saying replace every part but if part is original & suspect-replace it
Pro
Joined: Jul 2006
Posts: 635
Likes: 1
make sure you check the throttle shaft for extra play. Sometimes they can be worn and leak around it. When I checked my 93 for vacume leaks I found a lot of the hoses were brittle from heat and would leave black on your hands when you touched them.Also some of the hoses were kind of hidden, mostly by battery area. Way past time to replace them. It ran so bad I thought I needed to replace injectors but after replacing hoses it smoothed right out. Good Luck Tim
Intermediate
Joined: Jun 2009
Posts: 34
Likes: 0
For you guys that replaced yours, what brand/vendor did you get your new valve from? I have had mine out (just the valve, without removing the throttle body) and cleaned the passageway. This helped a lot, but I think the cold weather is making it stick or something. Sometimes it idles great, but sometimes not (and never when it is stone cold).
SB91
SB91
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Team Owner
Joined: Jul 2004
Posts: 28,429
Likes: 3,278
From: Hartford WI
Clean the whole TB first before buying a new one or it might work well for a bit and then stop working well. Ask me how I know.
clean the ENTIRE thing. That means take apart the IAC housing and all the passages. Then reset it so that the IAC counts area bout 15-20 and the TPS is right. At that point, you can determine if it is the IAC or not.
clean the ENTIRE thing. That means take apart the IAC housing and all the passages. Then reset it so that the IAC counts area bout 15-20 and the TPS is right. At that point, you can determine if it is the IAC or not.
Burning Brakes
Joined: Jan 2009
Posts: 1,199
Likes: 0
From: New Bern NC
St. Jude Donor '09-'10
For you guys that replaced yours, what brand/vendor did you get your new valve from? I have had mine out (just the valve, without removing the throttle body) and cleaned the passageway. This helped a lot, but I think the cold weather is making it stick or something. Sometimes it idles great, but sometimes not (and never when it is stone cold).
SB91
SB91
Intermediate
Joined: Jun 2009
Posts: 34
Likes: 0
Clean the whole TB first before buying a new one or it might work well for a bit and then stop working well. Ask me how I know.
clean the ENTIRE thing. That means take apart the IAC housing and all the passages. Then reset it so that the IAC counts area bout 15-20 and the TPS is right. At that point, you can determine if it is the IAC or not.
clean the ENTIRE thing. That means take apart the IAC housing and all the passages. Then reset it so that the IAC counts area bout 15-20 and the TPS is right. At that point, you can determine if it is the IAC or not.
Team Owner
Joined: Jul 2004
Posts: 28,429
Likes: 3,278
From: Hartford WI
Yea, I was planning on doing this when the weather gets where my fingers aren't going numb from the cold. I had previously just pulled the valve and cleaned out the valve area, but I realized that I can't get the backside clean without removing the whole TB. Just having the valve tip being clean helps, but it was pretty bad and I figure the rest is not helping.
Take the 3 cables off and 4 bolts. Loosen 2 clamps and you can take the heater hose off. Put in a bypass pipe while you are at it.
Take the TB inside.
