EM2 Ficial

Hi.

I have a 2001 Civic EX 5 speed coupe.
Long story short, I have this horrific idle problem.

Basically my idle bounces from about 1k rpms anywhere to 2k rpms.

I've:
Checked for vacuum leaks.
Replaced the map sensor.
Cleaned the IACV (Idle Air Control Valve).
Reset ECU and tried relearning the idle.
Replace Intake Air Temperature Sensor.
Changed Primary O2 Sensor.
Cleaned Throttle Body.
Adjusted Throttle Cable.
Replaced accelerator pedal.
Changed spark plugs.

NONE of which helped with the idle problem.

But heres the catch, when I start the car it idles perfectly fine, UNTIL I press the gas pedal at which the bouncing starts and continues for the duration of the trip. I can stop the car, start it back up, idles perfect... Just as soon as the gas pedal is touched, the idle problems start.

I guess I have a theory but need some advice?
When I unplug the IACV the idle smoothes out to a good 800 rpms and seems steady and nice. I have yet to drive it without the IACV unplugged [I'm scared] But if this is the case, does this prove the IACV to be faulty to a point where cleaning has no effect? Because when I cleaned it, it was disgusting inside with carbon deposits but I made it spotless when I was finished?

Or could something else be the culprit?

HELP ME PLEASE!

Thanks!

-EM2 Ficial

0go-part

Test the throttle position sensor

EM2 Ficial

I thought the TPS sensor on this car was like riveted into the throttle body and if faulty irremovable?

Sparksman

Ive wondered this myself if you can remove? Im holding my old oem H22a4 throttle body now, and it have the same rivets holding the TPS on.

EM2 Ficial

Yeah man its pretty much meant not to be remove, although Ive
Heard of some success stories of people pretty much cutting into the rivets with like a dremel or a hacksaw just enough to get a flathead screwdriver in and unscrew them? I dont think thats my problem though cause a faulty tps would cause just a hgh or low idle right? I have a fluctuating idle 0_0

Zedt3

Test the PCV Valve. I had this problem, that turned out to be the culprit. Had to get a new valve.

Ben Beatty

i have a fluctuating idle and my check engine light is on for a bad tps so that might be the problem

Sparksman

I wouldnt worry about the PVC valve imo. Thats an emissions thing that vents the head and crank case of pressure and gases. Most people run those to an oil-catch can anyhow. Shouldnt effect idle.

Yep, same as on my prelude but with no light. Idle bounced between 750 to 1,300rpm rapidly. Turned out the clip was broke and wiggled loose, ended up using a zip-tie and worked perfect until i pulled for a swap.

If you have the OEM TB and riveted on TPS. If that is the problem, you may have to buy a new Throttle body. H-B-D TB's are interchangeable if you have a buddy with one laying around. If you have a D put a b series TB on it not an H because it would be too big. If you have a B put and H TB not a D because would be too small. I wish i had exact numbers for you but i know im correct as long as you get an OBD2 TB for your car. If your car was OBD1 then you would obviously need a matching OBD1 TB for it to work. Or go buy an aftermarket TB and have removable TPS like i do now. Good luck!

Honestly all these will mess with you idle;
-TPS
-EGR
-FITV
-IACV
-Map sensor
-manifold sensor
-vaccum line leak
-manifold gasket leak
-recent mods/not tuned

hoppin blox

I had this same problem. cel? you may have ELD issues. replaced mine, pulled pgmfi fuse & relearned idle. ding. lemme see if I can find the thread for you. it stumped me cuz I tried everything from iacv to pcv,, no luck.


http://www.civicforums.com/forums/36...298-p1519.html


^^that's what my problem wound up being. after I went through everything else. never woulda guessed. best of luck to you.


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