Starting Issues

I will preface this by saying that I am no tech guru so I appreciate any thoughts or advice that may be found relative to a starting issue I have been experiencing with my vehicle. The following are the details:

Vehicle Details:

• 2013 Mustang GT 5.0 Premium Convertible
• 6 Speed
• 75,000 miles
• Recently replaced battery and spark plugs (after issue started)
• Car is driven very intermittently as it is now a "weekend car"
• No engine performance mods
• No check engine lights

Issue: (an example of what happens)

• The car starts perfectly fine (after sitting for a week or two)
• I drive the car 20 miles (mix of street/highway)
• The car remains parked for 5-6 hours
• When I go to start the car it cranks several extra times as if it is having a hard time turning over, and then (up to this point) will eventually start
• The car drives fine on the way home with no noticeable issues
• If I turn the car off immediately when I get home and then immediately turn it back on, it will start with no issue.

What the heck could this be? Any thoughts on where I can start with troubleshooting or evaluating?

I appreciate any help!!

Having a hard time turning over? Like slow cranking?
First thought is a weak battery, as it starts fine after a drive.
Measure battery voltage after it has been parked for the week and before attempting to start it.

Juice said:

Having a hard time turning over? Like slow cranking?
First thought is a weak battery, as it starts fine after a drive.
Measure battery voltage after it has been parked for the week and before attempting to start it.

Click to expand...

Up and till this last time it has cranked fine..just seemed to take a few extra. This last time though it sounded as though it was a slow crank.

Thank you for your reply. I will certainly do that and see what the voltage is. I originally thought it was the battery but I replaced it and the issue has persisted.

Could be the starter going bad, or merely turning slowly when it's heat soaked.

What was the condition of the spark plugs?. Did any of them in particular look gunked up or dirtier than the other spark plugs?? If so....
You have a bad injector. And it might not show up on codes.

flaky starter. mine did that and Ford had already replaced the battery, cables, and something else. I replaced the starter and never had another issue.

Starter, or...injector/fuel issue. What's your fuel pressure looking like???

I am providing an update should anyone in the future stumble upon this and be having similar issues. Per the recommendations, I ended up replacing the starter and the issue appears to have been resolved. Thank you everyone for the input, advice, and guidance.