idel problem

[adams86lxi]

Lately i have been siting in the school parking lot waiting to get out and the honda has been doing something weird at idel. It will sit their and rev from 1000 rpms to 1500 over and over and over real quick, and its kinda annoying. After i drive for a couple of min. it stops. My dad said it might be the water temp sensor. Do you guys know what this is? Thanks

BTW: the pgm-fi light has been comming on recently but i just turn off the car and restart it and it goes back off.

[AZmike]

Threving idle is probably air in the cooling system. The bubble will make you fast idle valve open and shut, giving you your weird idle. What code do you get from the ECU LED when you get the check engine light? The ECU remembers the last code reported until its reset (fuse pulled or battery removed).

[adams86lxi]

it will flash once and pause then it flashes again. I think that is the main oxygen sensor.

BTW: the pgm-fi light wasnt on when i checked it

[AZmike]

That's fine that the light wasn't on right then. Like I said, it remembers your last code. I'd start with the sensor and go from there. It might be a good idea to bleed your cooling system as well.

[adams86lxi]

alright cool, thanks!

[adams86lxi]

one more thing if i had a bubble in the cooling system would it do the idel thing all the time or just sometimes?

[adams86lxi]

alright found out the problem. The radiator was real low on water and that was causing the weird ideling. I still am going to eventually need a new oxygen sensor though. While i was under the hood discovered a vacuum leak. Does anyone have any good ideas about how to find the leak?