Long Time Cranking on Cold Start

[madtown986]

I have a 2002 Boxster S currently at 32000 miles. Mostly stock (Numeric shifter and cables are my only mods). I am pretty sure everything else on it is factory original.

When I bought it three years ago, it took a long time to start and was very weak cranking. Within three days of getting it home, it wouldn't crank at all. It turned out the battery was 11 years old. I replaced the battery and it's started nice and strong ever since. Turn the key, a couple cranks (about 1 - 2 seconds) and vroom - it's running. Instant like you expect from a new car.

Until a couple weeks ago. I had one or two cold starts that took a few moments longer than usual to crank. It cranks strong, it just took a little longer. It happened once, i didn't worry about it. Then it happened again. Maybe every 5th start or so it cranked a little longer before turning over.

Now it is happening every two or three starts and cranking for 3-4 seconds before starting. Those cranks are strong. It's not weak starting at all, just slow. It's mostly cold starts but it has happened once or twice on a warm start.

Fresh oil change within the past month. Oil level is good. Battery cables are tight. 93 octane gas from mostly the same place every fill up since i bought it. Once it's running, it runs well. No hesitation, mis-fires, ticks, or extra noise etc.

I'm in the deep south. Temps are warm lately (70-80F). It was starting faster during the winter.

Looking for ideas of where and what to investigate. Do these have a cold start injector specifically for cold starts?

Thanks in advance for any and all advice!

[Gilles]

I would check the Crank Positioning Sensor (CPS) as these get old and dirty ad could cause the symptoms you are mentioning

[madtown986]

Thanks. I will check that out. Is it easier to replace outright or is it worth cleaning up and reinstalling?

I have not checked for fouled plugs or cracked coil packs yet either. I would expect a mis-fire or other rough running if those were an issue. It sill won't hurt to check

[Newsguy]

At that age, if you lack records of the crank sensor, I would just put one in there.
But I wonder if you might check your grounds? They can cause this as they degrade.

[madtown986]

I think the grounds are good. all connections tight, no corrosion. They look brand new. I checked them in the past and checked them again last night. This car has had a pampered life (until i got it).

[997_986]

You could run an quality injector cleaner, it won't harm. You should pull the codes if there are any, maybe something leads you to a (starting) problem. Next question would be sparks -- you could do a visual check, but with that milage they have only 50% of their lifespan referring to the maintenance-plan. Fuel pressure could be worth checking as well.

[madtown986]

I've been thinking a quality injection cleaner would be a good idea in general. Do you have one you recommend? That might be worth its own thread. There's probably a lot of opinions on that.

I'm not seeing any codes from my generic OBDLink+ scanner. I do have an airbag light but I think that's related to the child seat thing under the seat not getting plugged in right when i took the seats out.

[Newsguy]

You might check those coils.
I remember reading coil packs might be a cause of similar problems. You’ll probably need to remove them, but look for cracks on top. They can be very small: hairline and tough to see unless removed. I wasn’t having trouble but when changing plugs, found 3 or 4 cracked. Replaced all for good measure. Some have smeared silicon over them but I find that just kicking the can down the road.

[997_986]

Originally Posted by madtown986

I've been thinking a quality injection cleaner would be a good idea in general. Do you have one you recommend? [...].

I use the Liqui Moly product, I think there is only one for petrol engines. I know they are suitable for that purpose an have a high PEA-content.
I would use Durametric or PIWIS for the codes, these generic readers sometimes detect nothing at all or are misleading.

https://docs.google.com/spreadsheets/d/1ugvGyiItUfgpNzy_DjkPt2VzAr3wCgkbcB6yWtv_IN4/edit?pli=1&gid=0#gid=0