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Wicked bad idle problem

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  #1  
Old 12-22-2009, 06:28 AM
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Default Wicked bad idle problem

Ok so i been having a bad idle problem for some time now. The idle you to surge from 300-1200 at times. But after cleaning the IACV, the idle problem has become worse. Now, while driving, i push in the clutch, the idle drops down to like 200 and then dies. At times, its plunges all the way down, then shuts off. Happens in all gears and all speeds, even at no speed. And it only happens when the car is warm. Any ideas?
 
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Old 12-22-2009, 07:27 AM
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Check that the FITV is closing fully with the engine warm. Make sure the throttle cable goes slack and the throttle plate closes completely. Put the test jumper in and make sure there are no ECU codes, and double check your spark timing. Disconnect IACV and adjust air screw on top of throttle body for steady idle around 450 - 500 rpm (engine warm). That should prevent stalling. If the idle again surges with IACV connected, clean it again it may be sticky. Or may need replacing. If it surges with IACV disconnected, could have a problem with TPS or other sensor, or an air leak.

Edit: and of course make sure cooling system is full, and bleed it of air.
 
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Old 12-22-2009, 09:33 AM
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thanks for the response..but im not that familiar with everything you said to check.
where is the FITV and how do i check if its closing. And i obviously check if the throttle cable goes slack when at normal idle, and i check the throttle plate by taking off the intake correct? when you say disconnect it, you mean disconnect the electrical part of it, correct? And ill try the disconecting the IACV and if it surges then its something else first.
 
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Old 12-22-2009, 02:27 PM
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pull the intake tube off, look insode the throttke body. you see 2 holes one goes to the fitv which is located underneath the throttle body and has 2 hoses going to it, and the other hole goes to the iacv, put your finger in each one, one at a time does the engine die? if one of them dont make any change then its bad. also do you have a cel?
 
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Old 12-23-2009, 05:06 AM
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no. my cel light is not on. but i will check for codes with the jumper thingy.
 
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Old 12-23-2009, 05:38 AM
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ok, so i did the throttle body hole thingy. i put my finger in the lower hole and it did nothing. i put it in the upper hole and it shut off. that means that the one connected with the lower hole is bad?
 
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Old 12-23-2009, 06:20 AM
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That's good. The lower hole goes to the FITV, which should be closed when the engine is warm.

What happens when you unplug the IACV wire? If the engine stalls, open the air screw on the top of the throttle body. It's a big flat-head screw, turn it counterclockwise. You may want to unscrew it all the way to check / clean the passages behind it.
 
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Old 12-23-2009, 06:23 AM
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i didnt do that yet. ill do it right now. so stay on the line. do not go anywhere. lol

edit: damn now i have to wait for the engine to get to idle again.
 

Last edited by Dipsetcivic117; 12-23-2009 at 06:28 AM.
  #9  
Old 12-23-2009, 06:39 AM
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ok i unplugged it, it goes like it wants to stall, but doesnt. car stays on but runs rough. plugged it back in and ran normal. is that what its suppose to do?
 
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Old 12-23-2009, 06:53 AM
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Yes it should run about 450 rpm (which generally means some shaking and "wanting to stall") with the IACV unplugged, you can adjust that with the air screw. Then it should go up to normal idle when you re-plug it.

I would try opening the air screw to get 600 or 700 rpm with IACV unplugged, if it can do that steady (no surging) that probably means the IACV is sticky and making it surge.
 


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