Car reving up and down
 

hi, couple days ago, I took my car to Mr. Lube to get a oil change and to get my fuel system serviced.
After everything was done, and the durty smoke stoped coming out of my exhaust, my engine revs up and down =S usally around 1-1.3k rpm
When I took it back to them they said they dont know whats wrong.
Did this happen to anyone before?
Oh and I am running a b16 and I got this like max 5 days ago and I have been driving my car everyday.
It doesnt feel sluggish or anything it just revs up and down when I idle.. and it would stop from time to time and come back within a min.. -_-!!

Could be a vacuum leak...

Pop the hood while it's running and listen for a hissing sound at idle.

probably a piece of carbon is causing the iacv to flux. Give the iacv port and TB a very good clean, if oyu must, remove and clean it

do what chris says. , take the iacv off , buy some carb cleaner spary it inside the iacv let it soak a bit drain it and put it back on then bleed the coolant.

And never get that fuel system cleaning from MR Lube. I have buddies that work their that wont even do it to my car because they "say so" . Theres a tiny write up on H-Tech on how to clean your iacv its a 20-30 min job. Good luck.

its an easy process... also try doing a tune up... if your cap has carroded (sp) ends and your rotor is shiat, then it was also cause a crap idle. If you do choose to do a tune up you might as well change the plugs, wires and fuel filter as well.

I tried cleaning the iacv and it wrked prefectly.
Thanks so much guys !
And it wasnt hard to do at all xD

glad to hear everything worked out... next time dont go the MR lube for oil changes..... they charge to much and some people who work there are questionable. Honda actually charges less for an oil change, and if its fuel cleaner you want, a good over the counter additive is the Royal Purple stuff I think or the redline additive... lucas also makes a decent one.

Damn, thanks for the advice xD!
This was my first time going to Mr. Lube to.
And I thought they were prefessionals.. but they chaged me almost 60 for a oil change O_o!!
Its funny, when I took my car back to them with the problem, they were like *we dont know whats wrong*
And they tried ripping me off.
I just flushed out my coolant and replaced it and they said I should replace it again O_o

make sure you bleed your coolant because air likely got in and once that iacv finds that air bubble it will start the surge again most likely.

next time you want an oil change pm me. **** mr lube. lol

damn.. but here's the weird part.
When my lights are on, it would rev up and down
But when I turn my lights off, it stops right away

alternator / battary ?!

*update*
I took out the iacv out again and cleaned it again with no problem
then I cleaned out the inside of the intake man. and NOW it finally runs quiet and normal xD
Thanks again for all the help everyone