All of a sudden I'm having difficulty starting, especially when cold. What I mean by that is that instead of starting immediately, it takes several seconds for the engine to catch. Starter motor turns just fine, so it doesn't seem like a battery issue. I'm at 55k, thinking that I'm due for spark plugs, so that was my next move. Car runs fine otherwise.

Any ideas?

 

I would start with the battery. Just because it " seems " fine I would still have it load tested. Any parts store can do that for free.
Never mind the spark plugs. They're high quality Beru or Bosch and can last up to 100K,changing them won't cure a hard cold start.

 

+1 for the battery check first. Easy to do and costs no money. The vehicle is a 2009 so the battery is nearing its age limits. Pull it and have the local auto store load test it. Do not close the frunk with the battery removed!

 

It's not the original battery. I meant to check the date on it over the weekend, but yes, it doesn't hurt to have it tested.

 

also clean the MAF. easy and cheap as well and causes of lots of weird problems. (might not be the solution but at least it's, uh, did i mention easy and cheap? )

 

I have an Autozone around the corner from work - battery tested good.
It ran rough this am for 30 sec after starting.
The plugs may last 100k, but Porsche calls for changes at 40k or 4years, which means I'm behind and that's why it leapt to mind. Though I thought I saw 50k somewhere.

 

ok, will drive past that Autozone again on the way home and get MAF cleaner.

 

You seem to imply that the plugs have never been changed... or it has been a very long time. 40k is the typical max. I'm of the opinion that could explain your problem. If never changed, very likely so.

 

Doesn't read like plugs. However, I dare say they are due to be changed based time. The concern is corrosion develops and this can result in damage to the head threads when the plugs are removed.

If you have left the plugs in past their change by date how about the fuel filter? The engine air intake filter?

I would have "guessed" battery as the couple of times one of my Porsches has exhibited a lazy start behavior it proved to be a battery. In one case I replaced the obviously bad battery with a new one only to have the new battery go bad in around 7 months. This battery was replaced with yet another battery which has held up much better.

(It could still be the battery. One time the battery checked out just fine in AM after I dropped the car off after having driven it to the dealer, but failed the battery test later in the day.)

Does the engine crank at its normal speed and just takes a bit longer cranking to start?

Slow to start may be fuel pump related (or fuel filter related) but this is not sufficient grounds to replace the fuel pump. (But again if that fuel filter is due or overdue to be replaced have this done.)

Not much you can do. You might check the battery cable connections at both the battery and where they connect/attach to the car. I have been told it can sometimes help a car electrically to loosen the fastener that holds a battery cable to the car or the alternator and then just retighten this fastener.

With the car dead cold start the engine then shut it off. Quickly but carefully check (feel) the battery cables for signs of heat build up. (At night with one car, not a Porsche, I observed a bad cable with some exposed strings of wire at a ground connection glowing red.) If you detect any extraordinary heat this can be a sign of a bad cable or connection.

 

I keep my jumper pack on the floor of the back seat. When I'm not carting kids.
No point having it locked in the frunk, with no power.

 

Don't want to harp on the battery. Just an observation.

I'm not incredibly knowledgeable about automotive mechanics, so please, anyone, call me out if I mis-speak. I always thought that the alternator will (I suppose through a voltage regulator) charge the battery once the car has started. If this is true, once you start the car and take to have the battery checked, it will have an accumulated charge. In the case of a bad battery it may not hold the charge and be just as low on power a few hours later, but it could show an acceptable charge level just after driving it (I suppose this would be a false negative) Of course I could be totally wrong about this.

As to running rough after start-up. Your battery may be totally fine but I had a battery go bad a few years ago. Cold winter day (well lows in the 40's is cold in CA), hadn't run it in several days, went to start - nothing. Counted to ten, gave it one more try and it turned over and ran rough for a short period (less than a minute). Drove around for a bit (presumably charging the battery via the alternator) and it started fine for the next few days before I changed the battery.

 

Yes, they are due. Not sure why I spaced that out. Would have been good to do when I had the mufflers off. Air filters were done. Fuel filter not. Is there an interval for fuel filter? Couldn't find one.

Engine cranks at normal speed, just takes noticeably longer to fire. Car is pretty much a DD, so it really was a sudden onset.

Car has had the HPFP recall done.

Autozone does a load test. I'll do a multimeter test in the am. I'll also check the cables.

Battery is not original, but the little date things are not punched. Older than 2 years is all I know, that's when I bought the car.

 

A failing battery may have a decent resting voltage but when placed under load, can not handle it and you can watch it dip well below 10 volts. If the car is taking longer to light off than normal but seems to be turning over at a normal rate then I would focus my attention elsewhere.

Darned if I know what the fuel filter change interval is. May not be one. Per my AllData, it is part of the fuel tank gauge and requires 1.1 hours to swap out. Pelican parts doesn't have a listing for a fuel filter.

Have fun changing out the plugs and cleaning the MAF. I think there is a decent writeup on the forum

 

Since the plugs are due for a change anyway, you might as well try that along with the MAF cleaning first. It won't cost you any more than you already need to spend anyway. If those don't fix it at least you've eliminated it for minimum cost.

 

Is it a bad tank of gas? Have seen this happen more than once.

If it was a 997.1 After a visual inspection I would recommend replacing the plugs and cleaning the MAF sensor because they are due. If I remember right the MAF sensor is ignored by the ECU when cranking instead it uses a set parameter based off the engine temp sensor. I would then scan the ecu and see what the sensors were reading, focusing on the coolant temp sensor. May also check cranking voltage at the battery and again at the starter solenoid +10.5V and for fun I would also check the voltage drop on the negative battery post to the body (there have been issues with the crank sensors and low voltage during cranking). To rule out fuel system problems would check fuel pressure and leak down and if all these items tested OK I would call you and ask for more Money