When I start my car (cold start) the car starts fine. When I do errands which means 3-4 stops at the stores. Once the engine is at operating temperature. My next stop, when I try to start the car, it wouldn't start but it would crank, then try to crank it 3-4 times with about 5 seconds gap between, then the 4th time, it starts....

I noticed this happens when the engine is warm.

I noticed this happens when I turn off the engine about 3-4 times with in the time frame of 1 hour, at least happens once everytime.

I changed the battery about 6-10 months ago due to it, and it didn't do it for a while. So I figured it fixed it. Now it started doing it again.

I had my battery checked today. It's a good battery. 12.3/ 687 amps.

So could it be my alternator or starter?

Input would be appreciated, TIA!

 

Could be corroded wiring. The wire that goes from the alternator to starter to positive terminal in the engine bay can corrode. The ground straps from battery to chassis or engine to chassis can corrode.

The alternator or voltage regulator could be bad.

The starter could be bad.

The crank position sender could be bad.

I've also read it could be the power distribution unit.

Have a look at this thread, hope it helps - sometimes my car would even stall at idle and had similar symptoms to yours:

http://www.renntech.org/forums/topic...ltage-problems

 

If the engine is cranking at normal speed you might be looking at a fuel system problem especially if it is warm.

 

Haven't had this trouble with a Porsche yet. My H2 starts on the 2nd try every time and I believe it is a weak fuel pump. However I had a Clk 430 that did as you described and it was the crank positioning sensor (CPS). If your engine turns then it isn't the starter. If you have juice to turn the starter it isn't the battery. The alternator wouldn't affect starting and if it wasn't putting out voltage your battery light would come on while running. I would lean towards the CPS.