Civic '99 CXi Idle surge when car is warm
 

Hi I have a Honda Civic CXi '99 model.

The problem is that the idle surges only when the engine is warm.

As per the tips I found here I did the coolant air removal thing.

But the problem is still there.

The thing I noticed is that the problem fixes itself if I remove the cable connected to the PS-33 Map Sensor.

Any ideas /tips.

Thanks.

Re: Civic '99 CXi Idle surge when car is warm (ezeedude)
 

Vacuum leak comes to mind. Spray some throttle body cleaner around the intake plenum (where it meets the head) and throttle body, if the motor stumbles or even dies it's a good bet you have a vacuum leak.

https://honda-tech.com/forums/images/smilies/embeer.gif
Mc

Re: Civic '99 CXi Idle surge when car is warm (ezeedude)
 

any CEL ?

Re: Civic '99 CXi Idle surge when car is warm (crazyguy)
 

No CEL will look at it tomorrow. Is there any code for a faulty IACV ?

Must also add that my car was parked for 4 months post which I got it driving and just also realized that Coolant was low and the expansion bottle was empty for at least a couple of months.

If it is the IACV can I soak it in turpentine to clean it out ?

Thanks

Re: Civic '99 CXi Idle surge when car is warm (ezeedude)
 

u can take out iacv and use brake cleaner to clean it. 2 bolts to loose and two coolant hoses to loose.

Re: Civic '99 CXi Idle surge when car is warm (crazyguy)
 

I am looking for an IACV that looks like this but cant spot it :

[IMG][/IMG]http://www.ff-squad.com/tech/sensors/iacv.jpg

Any tips people ?

Cheers.....

Re: Civic '99 CXi Idle surge when car is warm (ezeedude)
 

what kind of motor do you have? a D16Y7? i took apart my whole throttle body, its easy unscrew four bolts plus throttle cable bracket, cleaned iacv, replaced vacuum hoses. use a throttle body cleaner or brake cleaner, all good, i've had the same problem and fixed it

Re: Civic '99 CXi Idle surge when car is warm (ezeedude)
 

I too was experiecing the same exact issues you are facing.

I also have a 99 cx, and left the car sit for months at a time.

Anywho, before you do anything or spend any money, drive the car for at least 500 miles..

My cel code 14, idle issues, etc went away after "shaking the rust off".

Re: Civic '99 CXi Idle surge when car is warm (ezeedude)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ezeedude &raquo;</TD></TR><TR><TD CLASS="quote">I am looking for an IACV that looks like this but cant spot it :

http://www.ff-squad.com/tech/sensors/iacv.jpg
Any tips people ?

Cheers.....</TD></TR></TABLE>

Neither of those looks like the IACV on my D16Y7. If the USDM D16Y7 is the same as yours, it is connected to the throttle body by 4 screws. There are 3 sensors on the TB, the MAP sensor points up and is black, the TPS is cocked sideways and is black, and the IACV is mounted horizontal and is green plastic and aluminum. It has no black plastic as pictured above.

Mc https://honda-tech.com/forums/images/smilies/embeer.gif

Re: Civic '99 CXi Idle surge when car is warm
 

If you have a vac leak and you spray a combustible gas near the leak, the motor's idle will surge, not drop off.

Do you have a friend with a similar car whose MAP you can borrow?

Re: Civic '99 CXi Idle surge when car is warm (Blk00EJ8)
 

If you spray TB cleaner into your intake, it will stumble or even die if you don't increase the throttle position.

Re: Civic '99 CXi Idle surge when car is warm (mcvtec)
 

Have you ever done this? Throttle body cleaner, carb cleaner, brake cleaner... they're all flammable. Typical ingredients of throttle body cleaner:

Xylene &lt;30% - very flammable
Acetone &lt;30% - flammable
Glycol Ether &lt;30% - typically not flammable
Petroleum Distillate &lt;30% - very flammable
Methyl Acetate &lt;30% - flammable
Ethyl Benzene &lt;10% - flammable

How would flammable gasses in the air retard combustion in the engine? But I digress, as this is getting off topic...

I'm still inclined to believe it's a sensor problem, as a surging idle caused by a vacuum leak would likely occur even if the engine is cold.

Re: Civic '99 CXi Idle surge when car is warm (Blk00EJ8)
 

I plan to rip off the throttle body this Sunday and give the IACV a good clean.
Question is do I need some bits to be bought in advance ? I can see a gasket between the throttle body and the Inlet manifold, will I need a replacement for this ? Any other gaskets that I need ? Any other bits ? I have the brake cleaner for the big unclog. Any other tips / thoughts for the novice ?

Cheers & thanks....

Re: Civic '99 CXi Idle surge when car is warm (ezeedude)
 

Typically gaskets for your throttle body don't need to get replaced unless they rip. If you have a simple tool kit with a ratchet, metric sockets, and wrenches, you should be fine. Removing stock throttle body and IACV will cause you to remove coolant hoses so you may as well drain the system first, and then refill and burp it for air bubbles when you're done with the IACV.

Re: Civic '99 CXi Idle surge when car is warm (ezeedude)
 

Did the deed.
Pulled off the throttle body.
Pulled the IACV off the throttle body.
Gave the air section of the IACV a good dousing with Carb Cleaner.
Takes a bit of work and what no one in the forum mentions - The IACV has
a moving valve in it that rotates 180 degrees. This is the offending bit that jams
and causes the constant idle surge. Got this valve bit cleaned up well. Once it was clean it does a springy rotational movement of about 180 degrees.

Re-assembled all, bled the coolant and viola car is great again.
No Idle surge.

Cheers for the help and tips people.

Re: Civic '99 CXi Idle surge when car is warm (ezeedude)
 

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Re: Civic '99 CXi Idle surge when car is warm (ezeedude)
 

what kind of engine do you have? its a CX, it should probably be a D16Y7? does the intake manifold faces upward???