Good day Everyone. I have a 99-00 non vtec civic. I am having some idle problems for the past couple of weeks. When i start up an drive for approximately 15 mins, the engine jerks a little and the i could feel the engine idling like if its cold. I first cleaned the throttle an the iacv but still the same problem. I then installed a used throttle with all the sensors but the problem still exist. checked for vacuum leaks but there is none, also I bleed the coolant and replaced with new coolant but still the same problem. Now i'm told to change the tps sensor. Any help will be greatly appreciated.

 

Stop replacing parts and start doing diagnostic tests.

Any CEL codes?

When engine is hot and high idling, remove intake air system and use your finger to cover hole inside throttle body leading to IACV. Does the idle speed drop or remain abnormally high?