hard to start at times

2009 CHEVROLET COBALT
120,000 MILES • 2.2L • 4 CYL • FWD • AUTOMATIC
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WILLIAM CARVELL
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Here are the symptoms I have been experiencing:

-service traction light is on (not all the time (It comes and goes).
-shaking.
-stalling at low rpm's (in park, at stop signs etc.).
-misfiring in cylinders three and four (three being the worst)
-when I first start driving and I shift from reverse into drive, the car will jolt forward hard. Like it feels like I'm running into something. This only happens when the service traction like comes on.
-it can be hard to start at times, where I have to hold the key for a few moments until it gets going.


Any ideas? I have gotten so many different ideas, but none that seem to conquer all the symptoms. As a side note, I had gotten a tune-up a few thousand miles back. So the plugs and wires are new.
Jan 28, 2017 at 9:17 AM
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HMAC300
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It can be any thing form a basic engine problem , injector, sensor etc. for the traction control a mechanic is going to have to scan for codes to see if any are stored as any ABS problem will knock off traction control.
Jan 28, 2017 at 10:02 AM
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WILLIAM CARVELL
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My major concern is the stalling. Is there anything that would cause the car to stall that matches up with other symptoms?
Jan 28, 2017 at 10:08 AM
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SATURNTECH9
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The misfires on three and four cylinders could cause a stall. those coil packs go bad on those Ecotech engines and cause misfires. Is it a constant Miss fire? If so you can check for spark on cylinders three and four if you do not have any bad coil packs.
Jan 28, 2017 at 9:53 PM
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WILLIAM CARVELL
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I believe 3 was misfiring almost once every four revolutions. 4 was about half that. The plugs are new and I just put a new ignition coil in 3. I'm gonna get another one on four soon but I don't think it made a difference. I did however remove the throttle body and gave it a good cleaning. It no longer stalls on the road thankfully, but if it idles too long it will. I just replaced the air filter and dumped some seafoam into the tank to get rid of any moisture. What about idle air control valves? Could this be an issue? And where can I find it on my Cobalt?
Jan 31, 2017 at 10:49 AM
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STRAILER
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You have an electronic throttle in that model so you don't have a idle air control valve. Check for vacuum leaks in the air intake boot and clean the throttle body and mass air flow sensor and scan for codes, here are a couple guides to get the problem fixed,


https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

and

https://www.2carpros.com/articles/mass-air-flow-service

and

https://www.2carpros.com/articles/throttle-actuator-service

Please let us know what happens so it will help others

Best, Ken
Feb 6, 2017 at 1:44 AM