Sluggish cold start
 

My 2009 LT with 2.4 L starts hard when cold. Temperature about 30 F. When I turn the ignition key the engine turns over kind of hard and then starts as if it's is struggling. It then runs smoothly and has plenty of power. There are no codes. I put some dry gas in the fuel tank but so far it hasn't helped. Yesterday I tried turning the key to the run position and let the fuel pump run until it stopped. Then it wouldn't fire until I pumped the accelerator. It then started and ran fine. Today I just started it without letting the fuel pump run first and it started hard as before.

Once the engine is warned up to operating temperature the engine starts without struggling and runs fine.

What are the temp sensors reading? KOEO cold. Should match the ambient.

Battery?

Might be 1 or more injectors leaking down.

I don't know what would cause a sluggish starter motor in the cold other than a dying battery. I think that is what "engine turns over kind of hard" means.

My engine turns over harder when it's cold. Unless you have a heater they all do. If your battery is not up to snuff it may not have enough to start. Needs to hold better than 10 volts while cranking or the computer network will not be working.

A. the oil is less viscous in the cold making it harder to turn the crankshaft.
B. it takes more than 12 volts to make the the starter turn fast enough to start; cold affects battery voltage.
C. cold gasoline does not vaporize as readily as warm.
D. The EVAP purge valve might be sticky in the cold.
E. cold metal shrinks making for more resistance to moving.
F. the fuel pump has to work harder to pump cold gas; cold gas is denser than warm.
G. cold might affect the fuel check valve.
Probably some other thing.

I don't know how to read the temp sensors. How would I do that?

I had the battery load tested today. No problem with the battery.

I realize the cold makes starting the engine more difficult. I have been driving my HHR in the cold for a few years and it's never had this issue at this temperature. If it's much colder it will start slowly but doesn't struggle the way it does now. This problem seems different. It started a little better today so maybe the dry gas is helping. How long does it dry gas to work?

If an injector is leaking can that be tested?