One of my girls friends moms has been driving a 2000/2001 Chevy Cavalier without any issues until recently.

Out of no where one night it just started to idle a little rough. Its an automatic and when it would be in park the car would jump around, say usually it would stay around 1k or so, however now its been idling a tad bit high, 2k, and it revs by itself, sometimes up to the 5k point.

I dont know how much higher it would go or how long it takes it to come back down because as soon as it starts it I just shut it off.

Sometimes it just sits at around 2k when its cold started and will stay there for a bit until the gas is messed with and thats when it does its thing.

My friend told me it could be the Vacuum Line that lines from the TB to the Intake Manifold so Im checking that right now.

Im about to go check to see if it came off or if its cracked..

Anyone else have any ideas?

*UPDATE*

Replaced the Vacuum Line.. Same problem =X

 

Any vacuum line going to the intake manifold could be a problem. It's going to be something that is able to bypass a bit of air around the throttle body most likely, or something that can allow air right into the intake manifold, because it can't rev that high (5k) without the air it needs. It's probably something simple.

Sorry you have to work on a Cavi. I'd almost +rep you for that.

 

Sounds to me like a vac issue as well... Do the brakes work ok? Reason I ask is b/c I had a similar issue w/ a 4.3 s10 and it effected everything... Vac owns Chevrolets... Try seeing if the vac. ball is hooked up? Does the A/c and heater work or does it just blow air?

 

I replaced the vac line yesterday with an $0.83 one from Advanced.. No luck so far.


Cyanide, Im not sure as I havent tried driving it yet or messing with anything. I simply took the cracked Vac line off and put the new one on.

 

I'd continue to check for loose/cracked/disconnect vac hoses... Like I said, vacuum OWNS Chevrolets... They live off of it...

 

i would also check the condition of the throttle body and see if its dirty and gummed up if so gets some throttle body cleaner

 

All the other hoses looked in tact and not broke up hah.

Im going to have to remove the Heat Shield to look into it further!

 

Try cleaning the Maf sensor. A dirty one can make all kinds of trouble. Any codes? Is there a tach, and does it jump around? If so, then it could be the CPS (crank position sensor)

 

check the TPS (throttle position sensor), and see if the wires are in tact. Its located right at the TB.

 

Ok, thanks guys for the extra info! Im taking the heat shield off right now actually =D