2000 Civic SI stuck rpm & engine bucking.

[JAESN]

Hello everyone, I'm new to this site so bare with me. Ill try to keep this short and simple. After cleaning iacv my engine runs fine when cold but after 10-20mins of driving the rpm shoots to 1500 and stays there. When I give it VERY little gas the engine sounds like its clogged? And rumbles if I keep the pedal pressed alittle at constant pressure. Also, while stopped and on neutral the rpm remains at 1500 but the engine surges? And makes that clogged sound, up and down ever so slightly but rpm stays at 1500. Driving while at this state forces me to shift early or else the engine bucks. So at cruise speed, forget it. I go up to traffic speed limit and put my gear on neutral so I don't have to press the pedal.

I replaced PCV, Tsat, distributor, cleaned throttle, checked for vacum leak.

 

[firejackal]

Probably not the reason, but depending on if you removed the coolant lines on the iacv there is a chance you could of introduced air into the system.

Sent from my SGH-T999 using Tapatalk 4

 

[JAESN]

Thanks for the suggestion, I just "bleeded" out the air and bubbles were escaping but it's still acting up. Just wanted to know if anyone has similar issues.

 

[XpL0d3r]

I've had similar issues but it was with a faulty o2 sensor giving a bad reading. Check your o2 sensors. When the car is cold, it runs open loop, meaning it's strictly using the computer for air/fuel and not the o2 sensors. Once the car is warmed up it will use them.