Cold start cranking taking progressively longer.

[HBTD]

My 2015 GT convertible with 77k miles has been taking longer to start in the mornings. I live in AL and the car is in my garage all night so I don't think it is the cold weather. It has always started, but it used to start almost instantly when the starter button was pushed, now it takes a few seconds. I replaced the battery this spring, and the voltage gauge shows normal voltage (13-14v) when running. Any thoughts? Thanks for all advice.

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[Egparson202]

Time for new spark plugs?

 

[MAGS1]

Starter might be on its way out?

 

[Cory S]

What does the battery read with engine off at rest after sitting overnight?

When you say a "few seconds", are we talking 2 full seconds or just a guess?

 

[HBTD]

Time for new spark plugs?

Thanks, but I had the plugs replaced at the 60k service.

 

[sk47]

Hello; Spark plugs and a sound battery are places to begin which you have done. Things beyond that can be harder to identify. Another easy thing is the fuel but only if the car is stored or not driven very often. If a daily driver fuel is not very likely a problem.
A thing which comes to mind is the fuel rail pressure. On the FI vehicles I have worked on the fuel rail needs to have around 55 to 60 psi of fuel pressure. The fuel pumps can make much higher psi so a valve is usually installed in the fuel rail. Once the pressure is up to say 55 psi this valve opens just enough to bleed off excess pressure and send some fuel back to the gas tank. These valves move a lot of fuel over time and can start to not seal well.
When the engine is shut off the fuel rail is supposed to hold fuel in place. If that valve leaks off some fuel overnight then it can take the fuel pump in the gas tank a little time to push more fuel thru the lines and build up enough pressure. If the fuel rail has a test port a pressure gauge can be attached to check the fuel pressure. Some have such a test port. Other do not.

That said there are other electronic possibilities. Sensors that may be lazy (poor term). Not sure about starting and vacuum leaks causing a slow start.

One thing a slower start can do for us is to allow the oil to be circulated a bit before the stress of a cold start. I get we do not want such an advantage because of a problem.
Good luck

 

[HBTD]

What does the battery read with engine off at rest after sitting overnight?

When you say a "few seconds", are we talking 2 full seconds or just a guess?

The battery reads 11.5v before starting. It takes about 1 second to start, not long, but longer than it used to.

 

[Cory S]

The battery reads 11.5v before starting. It takes about 1 second to start, not long, but longer than it used to.

So, after 8-12 hours or so, a VOM directly on the battery only reads 11.5V????

 

[sk47]

So, after 8-12 hours or so, a VOM directly on the battery only reads 11.5V????

My 2015 GT convertible with 77k miles has been taking longer to start in the mornings. I live in AL and the car is in my garage all night so I don't think it is the cold weather. It has always started, but it used to start almost instantly when the starter button was pushed, now it takes a few seconds. I replaced the battery this spring, and the voltage gauge shows normal voltage (13-14v) when running. Any thoughts? Thanks for all advice.

Hello; Maybe you have a drain on the battery as it sits fora few hours. There are some factory things which draw power all the time but we hope the system is set up for that. Do you keep anything plugged into the 12V power outlets or USB ports all the time. Some of those ports are only live with a key on while others may be live with key off.
Another thought is the time/distance you normally drive. If you drive too little the alternator may not be able to replace the power used o start and run the car. The guy who runs a local small business - a battery shop- told me recently the charging systems of new cars have a hard time keeping up with demand as new vehicles have so many power using features. Guess what i am saying is if you run the AC at full blast +a stout stereo+ charge a phone+ have some extra lights or other add on stuff the battery may not.

Anyway I would expect a bit over 12 volts from a battery with the car shut down.

EDIT- Check the voltage at the battery itself with a VOM (volt Ohlms meter) set to direst current or the batt position.

 

[Rapid Red]

Sounds like the battery storage (AMP) cold-cranking power. Could be failing to store the energy it takes to turn the motor over.

The voltage reading seen may very well be what is known as a surface charge.

The only real way to diag is with a load test of the battery.

What is the battery brand & model type in the car now?

One more question, when starting the car. Do you allow a moment for the electronics to boot (stabilize)?

Or press a button going for the start with one quick jab. Not a great way to start the car.

The start button is not a light switch and does not operate the same The computer in the car and everything that has a computer.

Runs a post @ power on, checking the hardware and system parameters. That being things like sensors or battery voltage.

When they pass the post, the computer is ready processes proceed...... in this case motor turns over.

This is quick but jabbing the start button quickly can ask the computer to turn over the motor before it's done posting. The result the user finds a slight delay

"taking longer to start" is the delay occurring from the time you push the start button to the time the motor turns over.

OR the motor is turning over slower?

 

[sk47]

Sounds like the battery storage (AMP) cold-cranking power. Could be failing to store the energy it takes to turn the motor over.

The voltage reading seen may very well be what is known as a surface charge.

The only real way to diag is with a load test of the battery.

What is the battery brand & model type in the car now?

One more question, when starting the car. Do you allow a moment for the electronics to boot (stabilize)?

Or press a button going for the start with one quick jab. Not a great way to start the car.

The start button is not a light switch and does not operate the same The computer in the car and everything that has a computer.

Runs a post @ power on, checking the hardware and system parameters. That being things like sensors or battery voltage.

When they pass the post, the computer is ready processes proceed...... in this case motor turns over.

This is quick but jabbing the start button quickly can ask the computer to turn over the motor before it's done posting. The result the user finds a slight delay

"taking longer to start" is the delay occurring from the time you push the start button to the time the motor turns over.

OR the motor is turning over slower?

Hello; This is very interesting information. I do not own a newer vehicle with push button start but have tried out a few. First, I have heard anyone say anything about how to push the button. I do not quite understand how to go about this.

Back to the OP's problem. The car started more quickly before and now takes more time. It is possibly the way he is pushing the start button??

 

[Rapid Red]

Kind of what I'm thinking and he just discover it. It happen to me a few times and then realized what was going on.

We take a lot for granted in our push-button world. >smiling<

This Mustang is the first new full-boat computer control platform, for me also.

 

[sk47]

Kind of what I'm thinking and he just discover it. It happen to me a few times and then realized what was going on.

We take a lot for granted in our push-button world. >smiling<

This Mustang is the first new full-boat computer control platform, for me also.

Hello; I think I am beginning to understand. Not sure tho. If I do a quick jab at the start button the computer will still take some time to do the pre-start checks before the starter actually turns the engine over. Not much time to be sure. If we gently push the button some how the time lapse is not so noticeable?
Here is another question along the same lines. Can my idea of a lazy sensor or a vacuum leak or some other do-dad in the cars systems slow down the computers check list just a bit? This is a very vague idea. The first electronic fuel injection car i owned was a 1972 Porsche 914 with a basic system. Over the years of owning that car and helping others who owned those cars I learned to check vacuum lines and grounds early on when starting problems showed up.

 

[Rapid Red]

This is the symptom that gave me the clue, I got used to the push-the-button car cranked. Then intermittently it would power on and miss the start-up event.

Power off the car, then repeat start, it would fire, fine. The reason the computer had completed the post.

Think about if the car stalls, you push in the clutch. Reach over, and restart the car, no chimes why all systems were up and running.

The chimes are there for the post, but we humans can push the start button as the chimes are ringing and bingo, no start.

 

[HBTD]

So, after 8-12 hours or so, a VOM directly on the battery only reads 11.5V????

Not voltmeter, gauge on dash prior to actually starting.

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