hey guys, ran into a problem twice now, my rpms would fluctuate between 200-1200 rpms when i was at a stop, normally this happens when the car warms up and it isnt a big problem, except in these two cases where the car actually stalled. Now i wouldnt bother too much except this has happened twice in the past month.

some other info/particulars about each instance - i was low on gas (still was reading at the last mark about 1/4 tank). In one instance i was on a slight decline, the other a slight incline.

judging from what i've read, it could possibly be the 2.7" pulley causing the injectors to go static (running a gm stg 2)- but keep in mind i wasnt pushing the car hard prior to having it stall out, in fact i had only been driving for maybe 5-10 minutes before it cut out each time. OR it could possibly be bad gas, but i doubt it. I do know that i need to change my air filter relatively soon (its been about 10k miles since i've done it), but i doubt it would have this effect on the engine.

any other thoughts? i'll probably end up taking it into the dealership this week either way b/c my driver side door doesnt want to close properly (stupid cable is messed up AGAIN), so i'll have them look at that as well, but i wanted to see if anyone else has had similar problems, or if anyone could offer some insight into what may be causing this to happen...

....any ideas?

 

I was looking for someone who had this problem!!!! Mine done this twice today!! Once while slowing down to turn into my driveway (still going straight, clutch depressed and on a decline the car cut off as if I turned the key off). Second incident happened while stopping at a stop sign on a hill. Same thing though. Mine is a completly stock 2.2 with 70k miles on it (fuel filter has been changed, good air filter). Always ran shell or BP gas since it was new. Have you taken it to the dealership yet? What happened?

 

Same thing happens to my 07 SS s/c. Once in a while coming to a full stop the revs will bog to around 400ish and bounce from 400 to about like 1300, up and down. Never actually had it stall yet, though i was feathering the throttle to keep it from stalling.

 

My does this also...Hope someone has some insight on this..

 

Hey guys I just joined this forum because I noticed yall were having the same problem I was having with my Cobalt. I have a 2007 Supercharged Cobalt. I took mine to the local Chevy dealership to see what was wrong and at first they diagnosed the problem as blown fuel injectors. So I got those replaced and the original problem reoccurred a week later. I once again took my car back to the dealership and the technician then found the actual problem. The problem was the air filter. Each time my car revved up on its own, it was after a rain storm. The technician pulled my car apart and opened the air filter box and it was soaking wet. I personally held the air filter and it weighed 10x the amount it should. The air filter was completely rusted over. So if yall have a stock air intake, go get it checked out.

 

I just startedhavi g this problem. I have 2.2 sc. Ans it was my plugs. Were runningreally hot and caused the gap to go way off I kinda ignored it and it startedmisfiring. Do any of u have mods?

 

No, I don't have any modifications.

 

clean your throttle body. This has been a common problem with cobalts and it seems that a little throttle body cleaner has fixed it for most people.

 

Exactly... theres a sticky somewhere on here.

https://www.cobaltss.net/forums/2-0l-lsj-performance-tech-47/idle-problem-cure-finally-116051/

 

yeah i found the sticky after some more in depth searching...i also have a cai and i think the rain might be causing some flux too...but when it initially happened and stalled on me it was completely dry out. I gotta switch my filters soon so i'll clean the tb to be safe....

 

I've been having this problem as well for quite a while...I've cleaned the MAF sensor...changed the air filter(still running a CAI K&N typhoon) and sinceI work at an auto shop have a couple of guys I work with throw their 2 cents in....I'm also getting a CEL P0171...lean code....and from what my research has shown me I'm now down to 3 things..one...I could have a problem with an injector (either clogged or bad)...2 sinc eI have access to alldata I found a TSB concerning our stock ECU's....it stated that in some cases the 05-07 SS/SC ECU will sometimes need a recal or reflash...this also is a problem with my running lean condition....the third is it could be either the fuel pump or fuel filter..but I can find that out in like 2 min by chekcing fuel pressure....if I can find that TBS again.....I'll try and post it....

 

What part of Cali do u live in?

 

ventura county...I'm near oxnard...

 

I have an 07 SC. My car threw the same code. Mine was caused by a weak fuel pump so that would be a good place to start

 

this

 

ok..thats one area I'm looking at....so I'mguessing ya changed it out...how many miles did you have before you switched it out?...did it fix it?

 

I had problems with my 06 cobalt ss/sc the rpms would jump as you described and it stalled as well. Have the dealer check your throttle body if it needs to be cleaned that could be your problem, had my cleaned and she runs beautifully now. it cost me about 90$ for the dealer to clean mine and i haven't had a problem since.

 

i have this too, ill depress the clutch, come to a stop and my car will idle from like 500- 1000 and i gotta hit the gas a bit to make it not stall.

 

Mine kept doing that until i started to throw codes. P2135 then P1516.
Needless to say, I bought a new throttle body from the dealer. OMG everything is back to normal. Car feels better than before. My cost at the dealer was $105, retail $153.

 

very common on the sc when the filter gets wet. I have several posts around here about how to fix this. If anyone is interested pm me. I have posted this about 6 times now.. Its most likely a combination of dirty MAF/Wet Filter, dampness etc. You should clean your plugs and reset the ecu as well. Check your gaps.

 

clean out ur throttle body and intake!!! it takes 20 min and ur car will be back to normal!!

 

i think it was around 28k... Yea it was still covered under warranty but they did have my car over night cause they had to order the pump 5k later still no scent of gas so its doing fine