Idle problem

[riden2low]

Doing a search now and been reading and reading. The car is a 95 ATX. The idle has been going from 1200 down to 900 RPMS then back up. Was told the iac might be bad or to check for vacuum leaks. Used carb cleaner no change and I at least got the cleanest engine bay around here now. I have two cars, 93 and 95. So I exchanged the IAC'S. Same thing, surging up and down on the 95, the 93 ran perfect. So I ran the 95 a few days like that and now the issue is that the car idles at 500 RPMS. It will not idle until the car warms up a bit but yet at 500 RPM'S. So tonite I unplugged the IAC and the car keeps running at 500 RPM'S. Done the same thing to the 93 and it dies when the IAC plug is pulled. So the 95 has an issue somewhere and I can't seem to find it. I pulled the codes tonite too and got a 111. Weird huh? So my thinking is that I am not getting power to the IAC? Or why does it keep running when the plug is pulled.

 

[SHOGUN88]

If you pull the plug on the IAC and it keeps running there must be a vacuum leak.

 

[riden2low]

Thanks. This vacuum leak is driving me nuts. Still reading tho.

 

[riden2low]

One correction from my post, I did a test lite to the plug for the IAC and I am getting power. So the hunt goes on. So weird tho. I have had the car for 3 years now and the only thing I have done is changed out plugs, 02's and changed the oil. Other than that I have had no problems until now.

 

[rubydist]

with the engine warm, and the iac unplugged, the engine should run at about 500 rpm.

 

[sdpatt]

Have you tried to reset the idle speed? Sticky here.

 

[riden2low]

Yes, I have done the reset a few times but still nothing. Going to switch out the IAC's from the 93 to the 95. Bought a new IAC for the 95 and thought maybe it was bad but it works perfect on the 93. So I will switch them back again. And then I am thinking the 95 will do the idle surge again. And as I was told by Rubydist, look for the vacuum leak. Driving me nuts and the little woman breathing down my neck as it is her baby.

 

[LOUDSHO92]

You may also want to try and clean the IAB nostrils. They can get clogged.

 

[riden2low]

You may also want to try and clean the IAB nostrils. They can get clogged.

AH! Good point. Never thought of that. I have had the intake off of the 93 and cleaned every opening there was but not the 95. So that may be the culprit. Thank you!

 

[artsho]

When I unplug the IAC on mine it stalls...I'm also having idle problems...also when I go from drive to park the idle increases...

 

[riden2low]

Well, had to leave for a couple of days but am back and going to see if I can get this problem under control. I hope.

 

[riden2low]

Got back to the 95 ATX. Took the IAC off and looked inside the nostrils and looked pretty clean but still sprayed some cleaner thru there. Took an air hose and blew thru it too. But decided to take the the new IAC off of the 93 and put it back on the 95 and now the 95 is running again but still has the idle surge. Can go down the street with my foot off of the throttle and the car will go about 20 miles per hour. The tach is around 1200 to 1500 rpm. So have the battery disconnected and going to do a idle reset in the morning. Now as for the 93, I put the old IAC back on it and it won't idle now, so the IAC was bad but was okay before I started cleaning it. Maybe it was going bad anyways. Cleaning these things will cause them to go bad, like the cleaner going into the solenoid or something? As of now have to pick another up for my 93 arrrrrhhhh! So onward I march. Still a vacuum leak on the 95? Just have to keep plugging away.

 

[itwonder]

You might have gotten some liquid down in the IAC from cleaning, and its temporarily fouling up the operation. You can take them apart and clean them up. There is really not too much to go bad in there as long as the electrical part is good.

 

[riden2low]

itwonder, Thanks. I will see if I can get it apart. If not I will just order a new one. I noticed that most of the parts stores only give them one or two years on the warranty anyways.

 

[riden2low]

Tried to take mine apart but it looks like a sealed unit. Didn't want to try screw it up just in case it started working. When I get a new one, then I will see if I can get it apart.

 

[riden2low]

Did the reset on the 95 with the new IAC. It idles now but has a surge to the idle. Looking closer, I noticed the A/C was switching off and on. So I must be low on refrigerant. It was low once before a year ago. So that explains the surge at idle as it was going to about 1100 rpms then back down to 800 or 900. But still after letting up on the throttle going down a 25 mph street, the car still goes about 20 mph until I put on the brake then will slowly creep back up to 20 mph. Checked the throttle cable and no binding. Did a search and so far I have found others who have had the same problem but haven't found a thread that anyone came back to say how they solved or fixed the problem.

 

[rubydist]

it is supposed to idle at around 1000-1200 when the car is moving. only after it stops moving will the idle be reduced to the 750 range. what you just described is normal.

 

[riden2low]

Thanks Rubydist, You are probably right, at least on the 95 ATX. I know my 93 that I drive 99% of the time will drop to 800 or so rpms when taking the foot off of the throttle and yes it will still move at about 5 mph. To me thats more normal. Even my truck that is auto will do the same as the 93 ATX.

 

[riden2low]

Another thing will have to be done is to recharge the A/C so the idle surge is gone [at least for now] and I will have to do a front 60k. Found out the crank seal is leaking, so that will be in the works here soon.

 

[riden2low]

Back at getting to my problem on the 95 ATX. Thought the A/C was low but it is okay. Just can't seem to get my problem solved. The idle surging is being caused from the A/C going off and on. Now on my 93ATX, you put the climate controls to automatic setting and you hear the A/C engage off and on but it doesn't pull the idle down like it does on the 95 ATX. Every time the A/C engages on the 95 the idle drops to about 500 rpms. You turn the climate controls off, it idles but around 600 to 700 rpms. So am I still looking for a vacuum leak? Or is there a relay or something going bad?