Benjamin T

iTrader: (2)

this happened on the way to work this morning. sitting at the stoplight the engine rpms would suddenly rise to about 600rpm, then drop to 300-400rpm, and then repeat. it goes away with the a/c on.

the last engine-related things i've done is clean out my TB and reset a P0446 CEL that happened soon after using an OBD2 reader. this has all happened within the last 3 weeks. temperatures in the morning have been cold to the point of light snow last monday.

help?

Benjamin T

iTrader: (2)

nooo... it just got worse

i was heading back to the office after a meeting and i came to a stop at a traffic light... and the car stalled while in gear. it started up right away but the surging idle remains.

i am not getting a CEL.

ElitistK

iTrader: (4)

quick fix: turn on ac, or turn on parking lot while driving

do a serach...this has been discussed before.

milky

iTrader: (9)

if its too cold, you may want to let your car warm up a bit before driving off.

Benjamin T

iTrader: (2)

search under what term?

i've tried "surging" but nothing substantial came up. and this isn't the constant low idle problem most others have because mine jumps from 300 to 600rpms.

Benjamin T

iTrader: (2)

it's been cold like this since last november... this is the first time it's started to do this

tnbigdawg

iTrader: (3)

Did you remove the TB when you cleaned it? My guess is on a bad seal; try replacing that gasket. Otherwise it's probably a vacuum leak. I don't think it's a sensor since there isn't a CEL.

Benjamin T

iTrader: (2)

no i didn't take the TB off. i was going to, but i had bought the wrong gasket so the mechanic couldn't do it

he ended up using a can of carburetor cleaner and sprayed the throttle plate circumference, then wiped it down with a paper towel... or at least several towels because there was so much crap in there

i had checked the vaccuum lines that go to the intake plumbing after i had gotten the CEL last week, and i couldn't see anything out of the ordinary... but all i knew to look for was cut or loose/disonnected hoses

chuckb

the low idle prob isn't a surge. it just idles low and stays at about 400-500 rpm.

Benjamin T

iTrader: (2)

i tried turning the a/c on... the surging stops, but the you can see the idle fluctuating on the tach.

but here is the bad part: when i shut the a/c off, the engine stumbles and will stall if i don't step on the gas.

GSteg

iTrader: (15)

On the throttle body, there is a plate that you can take out to clean. If you dont know what i'm talking about, here are the pics:





The holes are the main source of air inlet at idle. If the holes are clogged, your idle wont be smooth. Mine was black inside and some of the holes were clogged. Now my idle is smooth Use your carb cleaner. Take out the throttle body and clean it up.

If you already did this, then disregard my post

Benjamin T

iTrader: (2)

no i didn't take the TB off... i definitely didn't do what you've shown above. thanks very much for those pics... did you have to replace that particular gasket?

GSteg

iTrader: (15)

No I didn't have to. I think the gasket was metal. I took that picture 10 minutes ago. But it was definitely not rubber. Just take it out slowly and carefully. Use the carb cleaner to clean the gasket too to make sure there isn't any debris on it. Hopefully that part of your TB is dirty because then it gives us hope that it might be the reason why your car is surging.

Benjamin T

iTrader: (2)

thanks very much for your help with the pics... i've contacted the mechanic and he's going to try and tackle this tomorrow... here's hoping

GSteg

iTrader: (15)

You may even check it right now without cleaning it. I'm anxious to hear the results!