"Help"
 

Hi Guys,

I have a boxter 986 2002/2.7 tiptronic, for a while now I have a situation that when you start car it goes up to normal temp then cuts out. you have to wait until temp is back to zero temp before start again and this is stationery when driving will stop sooner once up to normal temp. checked on computer no faults showing. when first started happening would crank no start then start and you could travel 100 mile say stop car and ity may not start for ten minutes but you could do another long journey. but now 10 minutes max ? changed plugs, checked all connections appear to be ok. fuel pump sounds ok, tried running car with maff sensor out still cut out. 2 concerns i have 2 duff remote keys that dont open vehicle remotely but manual yes, but surely would not let me start car at all ? what about a new crank position sensor ? I have one to fit. finally the car will start when cold but cuts out when hit normal temp. I am not really motor minded and would value any ideas not tried cheers guys..

Wish I could be of more help but maybe heat soaked electronics or vapor lock? Maybe the fuel pump stops operating when the car gets to operating temps? Have you checked the wires on the CPS make sure they aren't cracked?

Once it's dead, and then you crank it to start, does the tach needle move??

If not, then the CPS is probably gone bad.

I'd guess CPS. Just a guess because I have read they are known to function cold and fail hot. And a failed CPS would stop the engine dead as you describe.

My CPS experience (though on a late 90s Jetta and Civic) would lead me to believe that's it as well.

Sent from my LGLS775 using Tapatalk

Suggest a Search for 2 tests
1. Tach needle bounce
2. Ohms at CPS connector.
https://www.youtube.com/watch?v=9bLHL06eNvo
BTW it is called(in Posche-speak) Crankshaft Reference Sensor Part # 986-606-112-02(for mine)
No need to guess. At least it is an inexpensive (Bosch)and easy replacement.
Porsche Boxster Engine Sensor Replacement - 986 / 987 (1997-08) - Pelican Parts Technical Article
Pelican Parts

I have an 01S with 150K. Last year, the CPS failed. Symptoms were: 1) start car, 2) run to get up to operating temperature, 3) purposely shut off engine, 4) try to restart, no joy. If I let the car coll down for 20 minutes, the engine would restart. Replaced the CPS and never saw the problem again.

So the cold / hot phenomena is real.

Try the two tests and I'll bet you'll find a bad CPS.

Maybe obvious but what is CPS?

Crankshaft position sensor

Could also be Fuel Pump relay as symptoms are similar. Mine would get hot shut car down. Car would crank but not start. Let it cool 10-15 mins and it would start up and run until hot again, repeat.

It was hot to the touch. it can be jumped for testing and it's a cheap part.

Fuel pump relay- the "Tach needle bounce test " would eliminate that easily. The CPS ohm test would confirm.
Smart suggestion because it is easy to fit the spare relay (oddball style pins)for the fuel pump that you always carry !or the diy jumper cable to bypass the relay
996-615-101-00, Note the small 5th pin. No Auto Parts store in the Boonies has that !
Pelican Parts

http://986forum.com/forums/456686-post9.html

Ahh....thank you