I just bought my Honda Civic 99 HX!! But I've noticed that the RPMs Move up and down when the car is warm and when I come to a full stop that's where the needle moves up and down kinda like it wants to turn off it does that one or two times then goes back to normal once I drive it but again this happens when I come to a full stop.. I know this isn't normal what can I do to fix this problem?

 

most likely you need to clean the iac (air idle control motor). remove clean inside with some brake clean reinstall

 

YOU NEED TO REMOVE THE IDLE AIR CONTROL VALVE AND CLEAN IT. WHEN YOU ARE DONE IT WILL RUN MUCH BETTER. WHILE YOU ARE AT IT GRAB A BOTTLE OF SEAFOAM CARB CLEANER AND CLEAN UP THAT THROTTLE BODY.

GOOD LUCK SON.

 

You guys have any pictures so I can follow step by step.. Civic Hx 99

 

Is this always when its just idling or does it stop and settle down after you come to a stop??? Low coolant will cause it to idle funny...

 

It settles down after I stop for a while at a stop like if it's trying to catch up..

 

I've cleaning The throttle n the iac valve n it's still does it..

 

Crazy - turn off the caps lock.

 

Have you checked for a vacuum or intake air leak? CEL codes?

 

was just about to call him on that lol.

 

The CEL is PO505 P

I had to reset the ecu cuz before I had the p0420 but I had that already fixed so now the P0505 Comes on

 

Remove the air intake system and, when the idle is surging, use your finger to cover the hole/port leading to the IACV. Does the idle speed settle down? If not, you have an intake air or vacuum leak. If so, start by adjusting the idle speed as per instructions in the service manual.