idle riding high and wont come down..

[nofear3544]

Okay so his problem began a few months ago when the idle started to fluctuate and when I started the car cold, the idle would drop (sometimes stalling) and i had to give it gas until the car warmed up. After driving if I stopped at a light the car would rev normal but a check engine light would pop up for the afm. The car felt like it was using a bit more gas than normal as well.

 I recently replaced the afm with a brand new re manufactured one and now the idle does the same thing but its pulling a code for the o2 sensor. Now though when I stop at a light the idle does not want to come back down, it sits over 1100 rpms and just stays there until i take off again. could it be a bad o2 or is there another problem that could be triggering the sensor. I feel like there could be more gas being forced into the engine.

[twright]

Is the throttle stuck open?  When it's idling fast open the hood and try to manually close the throttle by hand.  If it does, somethings not right with the throttle body.

[AcSchnitzer318is]

Does it still do the initial start fluctuation problem?  If you are lucky your o2 went bad and replacing it will fix your problem.  If you are unlucky like so many others on this board, you'll replace the o2.  Car will run dreamy for a few hours or longer (depending on how you drive).  Then you'll be back where you started.  That's what happened to me anyway.

If you figure it out plz post the culprit.

[nofear3544]

i have messed with the throttle when it seems stuck and there is no difference everything is working as it should. I am planning on taking it down to a shop tom to have a friend look at it. I do believe i may have a bad o2 along with faulty houses under my intake manifold. As soon as It is fixed or the problem is diagnosed I will post it.

[tjts1]

I have my money on massive vacuum leaks in the hoses below the intake manifold.

[Jimmy Lewis]

I have my money on massive vacuum leaks in the hoses below the intake manifold.

You would, haha. It seems the TB heater delete and subsequent vacuum hose replacement is more of a maintainance step these days. Everyone is doing it, you sir are a trend setter.

[tjts1]

What can I say. I stick with what works.

[E30tii]

Might be the valve cover breather hose.

[AcSchnitzer318is]

What can I say. I stick with what works.

Didn't work for mine  Though it did make the engine bay a whole lot tidier.

[nofear3544]

okay so the task of deleting the mess of hoses is complete but there is still no change in my idle.. actually its kinda worse even though I found a giant hole in a hose. I checked my codes and it was pulling a code for emissions (its code c9 using the peake tool). Im not sure what this means exactly but I just had my O2 sensor replaced today and the CE light is only coming on if the car idles for a while. Im going to try and clear the code and see if it comes back. it might just need to be cleared since the new O2 was installed.

[xwill112x]

icv

[Cobra Jet]

icv

EXACTLY.  

When the ICV starts to go bad, the symptoms you describe is only ONE of MANY for a bad or fouled ICV valve.

Do this - start the car, once it gets to normal operating temp and while the car is at idle - get a small hammer and tap the metal exterior of the ICV valve...  upon doing this, you should experience an immediate idle fluctuation - it could go higher, lower or stall...

Now, remove the ICV from the vehicle.  Get some electrical cleaner (available at most parts stores and I think it's manufactured by CRC - red & white can, black top).  Turn the ICV upside down, squirt the cleaner into the ICV until it starts to flow out of it or it overflows...  Prop the ICV up against something so the cleaner won't leak out.  Let it sit for roughly 10-15 REAL minutes.  Pick up the ICV after it has sat, cap both holes to the ICV w/ your fingers and shake it vigoriously, then dump out all of the liquid cleaner.  Repeat the soak & shake process one more time, only this time, take a hammer and tap around the entire exterior casing of the ICV.  This tapping will dislodge any other carbon particles from the interior (you can tap it pretty hard - but not too hard to dent or break anything).  After tapping the case, cap the holes, shake and pour out the cleaner.  Let the ICV sit to dry for about 5-10 REAL minutes, then reinstall.  After reinstalling you SHOULD experience better idle, better drivability and smoother operating ICV.

If after reinstalling if you don't experience ANY changes at all - time to buy a new ICV (which runs about $130.00+ depending on what vendor you buy it from).

I've been able to bring my ICV back from the "dead" multiple times so far - just needs a few taps & a cleaning and it's good to go for months at a time.

The issue is, an ICV that's never been cleaned has a ton of carbon build up inside of it, which hampers the internal spring/valve operation and causes it to stick (when it sticks, it could stick closed which would create a non-start or stall issue, it could stick partially open which would cause low idle and idle problems or it could stick wide open which would cause very high idle).  Once an ICV is cleaned, it usually works normal again.

[nofear3544]

cool thanks for that info, ill def try cleaning it.. I did reset the ce light and and after driving it around town I'm still pulling a code. If you check it with the tool it says emissions and if I check it manually using the gas pedal I get a 1222 for oxygen sensor.

[Cobra Jet]

If the O2 is old w/ many miles on it, or if it may be original - replace it.  O2's are really only good for about 40,000-50,000 miles, then they should be replaced, as they are not "lifetime" parts.  Some vehicles will throw a code for a bad O2, while others do not, because the DME (or brain) will try to compensate for the bad O2, sometimes causing problems w/ the air to fuel ratio (car may run rich or lean and you'll notice this in your gas mileage).

[nofear3544]

I just replaced it because of the code and its still showing 1222 even though the car is running better.