cleaned my IAC, now barely runs!!

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BDEUCE
Posts: 135
Joined: Wed Jan 03, 2007 8:24 pm
Location: Canada's Yukon

cleaned my IAC, now barely runs!!

Post by BDEUCE »

i took it off the initake, removed the bottom part, and cleaned the whole thing with carb cleaner. i replaced the o-ring, and cut a new gasket out of a gasket sheet. now, it doesn't want to idle, and if i feather the gas, i estimate it's idling about 200 rpm - limping. lots of power, grunt is there, top end is there. i unplugged the electrical connector at the back of the iac while it was running, and no change. i pulled a vacuum line, and roar! it leaps up to around 900rpm, put it back on, stalls. is it possible, i wrecked it by cleaning it? used inferior gasket? if it had a leak in the gasket, would it do this? i adjusted my idle screw up a turn, and now it idles (barely :puke: ) at about 500 rpm. any ideas?? i looked at my vacuum lines, they're all good, pcv is not that old, but i'll check it. when i first start it, there isn't even enough rpm for the alternator to start charging until i give it a rev. oh, 1990 2.9
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Nobody
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Post by Nobody »

Sounds like the IAC isn't opening. Or your vacuum line is plugged into the wrong place.
Paul
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Location: Marysville, Indiana
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IAC

Post by Paul »

so you cleaned the IAC and put it back on and it quit working, sounds like you need to check the plug connection, the plug itself might not be making connection, make sure the wire didnt push back in the plug end, also take a minut and run 2 jumper wires to the iac and see if it will open and close, just run them from the battery one is positive and one negative going to the iac itself, you should be able to see the plunger inside move........... cahnces are its in your plug though, because the IAC itself does not run off vacuum...... but the truck should only drop about 200 rpm if the IAC is unplugged, you should probably check the connection on the TPS instead..... its located directly across from where the throttle linkage hooks up. if it has came unplugged it will drop the idle on the 2.9 so low it will barely start if it even does then............ but cleaning the IAC should not make it stop working, unless you managed to jam it while cleaning it...... so unless you took it apart it should be perfectly fine........ if you took it apart, then you didnt get it put back together right, the IAC is no more than a simple air solenoid...... or an electromagnet, an plunger, a port that opens when the magnet is energized because it pulls it back and a spring behind the plunger to push it back shut, if you took it apart to clean it, then you should disassemble it again and check to make sure its not jammed if you didnt take it apart, then you should not do it now........... you said you replaced the o ring so i assume you did take it apart, did you oil the o ring with a light oil.....3 in 1 oil when reassembling it????????? because i am assuming you did take it apart to replace the o ring inside it......... if you didnt oitl it, you should have......... but also are you positive you put the stem back in the right way becasue if its backwards or any 1 piece is backwards it will not actuate................ but i would definatly check the plug on the Throttl Positioning Sensor, if it isnt reading back to the PC the motor will run like shit...........and or not idle right.......
1989 Bronco II 4x4
Mitsubishi 146 5 speed,
Stock D35
235/75/15
4.0L upgrade
NO LIFT
Crop Top
BDEUCE
Posts: 135
Joined: Wed Jan 03, 2007 8:24 pm
Location: Canada's Yukon

Post by BDEUCE »

i did infact take it apart - but i didn't remove any pieces. i separated the two halves, and kept the rod in one side, sprayed carb cleaner, shook out pieces (kept my finger on the rod so it would stay there, and repeated. let dry for about 20 min while i did my oil change (perfect oil change no hassles, no problems i can think of that would be associated). i re-assembled the two pieces, replacing o-ring inside. i did not oil it. :frown: i cut out a new gasket, which was basically boxboard - like a cereal box material. tightened the two bolts in the intake, plugged it in gently, and nothing. i didn't damgae the plug while removing it, and i also put dilectric grease in the terminals too. i'll have another look at the plug, and also disassemble the iac again. i'll test it on the battery like you said, and see what's what. if that works, i'll show you a picture of everything i have inside, and maybe you could tell me if it's wrong. going to pull it off now.

nate

(thanks for your response, too)
BDEUCE
Posts: 135
Joined: Wed Jan 03, 2007 8:24 pm
Location: Canada's Yukon

Post by BDEUCE »

okay - oiled it, and examined the plug, put it back on, and it idled beautifully. i guess something was sticking? seems to work fine now. - i had adjusted that screw on the tb about two full turns to get it to run before, and now the screw is backed off so it doeesn't even touch the rod.

thank you for your help.
BDEUCE
Posts: 135
Joined: Wed Jan 03, 2007 8:24 pm
Location: Canada's Yukon

Post by BDEUCE »

wow what a dumbass i was. it runs really good now. guess i missed that part about the oiling. :laugh: i think it idles really high now - i have an exhaust leak and live in a condo - it's louder than it used to be at 7 :30 am. i'm getting some of these :flipoff:

thanks again for the help - this place is the best.
Paul
Posts: 231
Joined: Tue May 01, 2007 4:57 am
Location: Marysville, Indiana
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o Rings

Post by Paul »

o rings are used as seals in hydraulics and phnuematics always oil an o ring on assemblhy for future uses just like the o ring seal on an oil filter, but i am glad to hear it fixed your problem......
1989 Bronco II 4x4
Mitsubishi 146 5 speed,
Stock D35
235/75/15
4.0L upgrade
NO LIFT
Crop Top
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