Need help with idle issues

everymistake

New Member
1997 Honda Civic Ex

My car overheated a while ago, and it threw an Idle Air Control Valve (IACV) code. I made sure the coolant system was repaired. It's the winter season here in Missouri, and when I started my car in cold weather it would NOT run until the engine is to normal temp, but even then it idled very, very low, to the point of dying or almost damaging the engine. (if possible)

So.. I then took off my IACV to check it out, and it was a disaster, so I replaced it. Currently, when I start it in the cold, it will die. But, when I start it a second time and rev it at about 1.5k rpms for a second or two, it will stay running but at a very low rpm. Sometimes though, when it's up to normal idle temp, it will either run at a very low rpm, or vary to a high 1,500 rpms. But it doesn't fluctuate from one to the other, it's either a very low idle or a 1500 idle.

When I changed the IACV I disconnected battery, but I did not do the "turn it on cold and rev at 3000rpm until normal temp is reached, then turn off and start again. Any tips on what else could be wrong? Check engine light is off, but it still idles ridiculously low or on rare occasion at 1500rpms.
 

MistahJuice

100% real juice
Registered VIP
5+ Year Member
10+ Year Member
Ah I wasn't sure. Well then OP have you checked for vacuum leaks and did you reset the ecu after you changed the iacv, or did you just clear the code? Hopefully RonJ will see this and drop some knowledge on you.
 

everymistake

New Member
MistahJuice said:
Ah I wasn't sure. Well then OP have you checked for vacuum leaks and did you reset the ecu after you changed the iacv, or did you just clear the code? Hopefully RonJ will see this and drop some knowledge on you.
Click to expand...
I reset the ECU, but I read somewhere you need to turn it on cold, run it at 3,000rmps until its up to temp, shut it off and start it again. Have not tried that yet. Today when my father gets home we're going to check for leaks. I reset the ecu, before I started the car but when I did start it the code was gone.
 

everymistake

New Member
Okay, so I checked for leaks on the intake, and there were none. It's all sealed up tight. What else can I do? Still has a super low idle on start up when cold and goes to 1.5k rpms when its hot (every now and then) I turn on the ac and it will drop to a good idle, but it doesn't last for long.
 

everymistake

New Member
Another thing I should mention, idk why i didnt, i got a new engine out in, and i had them install a skunk2 intake manifold, but the thing the throttle cable spins around, it was catching on the manifold so the throttle was very sticky and revved too easily, so we ground it down so it would spin freely. But we couldn't get the idle to go back to normal, so we adjusted it manually. Did we cause a problem here?
 

RonJ

Banned
everymistake said:
Another thing I should mention, idk why i didnt, i got a new engine out in, and i had them install a skunk2 intake manifold, but the thing the throttle cable spins around, it was catching on the manifold so the throttle was very sticky and revved too easily, so we ground it down so it would spin freely. But we couldn't get the idle to go back to normal, so we adjusted it manually. Did we cause a problem here?
Click to expand...
Post a picture of what you ground down.
 

everymistake

New Member
[/IMG]

We then adjusted the idle with the nuts on idle, because after we ground it down it wouldn't even start because of all the free slack.
 

RonJ

Banned
The diagram below from the service manual says it all. Never touch the throttle stop screw. I recommend that you buy a new unmolested throttle body.

 

everymistake

New Member
I did not touch the screw, the throttle link, i suppose it's called, was not even touching the screw. That is why we ground it down so it would. then it would not start because the tension in the throttle was lost, so we adjusted the throttle manual with the two nuts that allow you to tighten and loosen the throttle. I was having the idle issue long before we adjusted it.
 

everymistake

New Member
It now looks exactly as that picture, the throttle cable is not loose, just barely snug, and the throttle link is now touching the screw. As i said, did not touch the screw, just allowed the two to contact. The reason they werent was because the throttle link was sticking on the intake manifold, so we ground it down so it would reach the screw.
 

everymistake

New Member
So i believe if i do the step by step procedure someone posted at the bottom of page one, i hope, will solve my problem. The only problem i see, is that we adjusted the throttle CABLE, with the two nuts that you can adjust the tightness and looseness of the cable with. where the rubber piece over the cable is. Do you believe that will have an effect? Tomorrow i will try the step by step diagram as mentioned above, and let you know how it goes. You all have been of great help. I do believe the throttle body setup is perfectly fine, Im just worried about how we adjusted the cable.
 

everymistake

New Member
In better words, the mechanic who put in the new engine dismissed the throttle link not touching the screw as fine, and my throttle was super touchy (because it was stuck on the manifold, it was hard to push the peddle down without hitting 3000rpm to break it lose from the manifold), so we made it touch the screw by shaving it down so it wouldnt stick on the manifold anymore. But after we did that, the throttle cable was set up where it wasnt touching the screw, so we lost all throttle cable tightness, it was completely loose at this point. That is why we tightened the cable with the nuts to allow it to idle at a decent speed, because there was a lot of extra slack and it wasnt pulling the throttle link at all until the pedal was about half way pushed down. Do you get what I am trying to say? If not let me know and i will take pictures tomorrow morning and another full description will be posted. Sorry about all these posts, just trying to get it straight
 
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