Starting problems....

[dext986]

Hello all.

My 2000 Boxster, runs like a dream, but has just one little problem...
She starts first time every time...without fail.
But.....
If my first journey of the day only lasts about 15 minutes, and I go to restart it again after 10-30 minutes, she won't fire up. She will turn ok, but its like petrol is just not getting there. then after about 30 minutes, she fires up and great for the rest of the day.
If the journey is more than 30 minutes, I can stop and start it no problem.
It only happens if the first journey is a short one.....
Any ideas???
I changed the breather valve on the filler nozzle.....someone mentioned something to do with the choke might be sticking?

Any ideas appreciated before i take it to a dealer to look at and have to sell a kidney or something....
Thanks

 

[Glyn]

You really do need to get the codes read otherwise its all conjecture and could end up costing you a lot more.
If you identify the area you live perhaps someone on the forum has a Durametric and would read the codes for a beer or two, alternatively, you could get a cheap OBD2 reader online (about £30), read the codes and post on here to get the diagnosis.

Clearly the issue is most likely to be heat related in that a short run in which you don't get to normal running temperature is confusing a sensor.
However - which ones? Could be the temperature sensor which has a dual role in that it provides a feed to the temp gauge and also to the ECU to richen the mixture when cold (two separate circuits in one sensor)
It could be an oxygen sensor - again this affects fuel/air ratios, The MAF also has a temp sensor.

All temperature related sensors feed the ECU - and that directly affects fuelling ratios, you could be running very lean or very rich, but once up to temperature your sensors are within tolerance and everything works fine.
It seems when your stone cold or full hot your car is fine, therefore its my conclusion its a temperature related issue.

Good luck

 

[dext986]

Thanks for the info Glyn....
I never thought of trying to get the codes....I have been toying with getting one of those as the prices are now really cheap.....might be a good investment...
i am on the same thoughts but not technically minded to understand it all. Apart from this little issue she runs like a dream....

 

[dvenman]

Depends what you're looking for, but I bought an Autel MD802 off eBay - http://www.autel.uk/products/professional-scan-tools/maxidiag-elite-md802/ - got quite a deal on it, paid less than £200, the cheapest on eBay right now is about £220.

It will read and interpret codes not just for the Porsche range but quite a few other vehicles too.

 

[pgk188]

Do you know if this tool be used to re set the service indicator?

Thanks

 

[Glyn]

I think the Durametric (besides Porsche piwis) is the only dedicated to Porsche OBD2 reader on the market that can read codes and all modules and do service/airbag resets.
It is a fantastic tool, About £300 though for the enthusiast version and only reads up to three different vehicles - unless you buy the professional version around £800 and no limit on the number of vehicles.

But for general code reading a cheapo £30 reader will do

 

[dext986]

I read about the cheap ones, and they seem to do the job. At least it might point me in the right direction.....

Are these sensors expensive and easy to do? Or is it a dealer job?

 

[dvenman]

The job itself - have a look here - http://www.pelicanparts.com/techarticles/Boxster_Tech/19-FUEL-02_Sensor/19-FUEL-02_Sensor.htm

The O2 sensor ? Check Design911.co.uk, about £100 plus delivery and VAT.

 

[dext986]

thanks for that link....you have to love pelican parts!!
Looking at the text though, mine has none of those problems indicating the O2 Sensor. It runs sweet, it just won't fire again for about 20-30 after a short run. It has no problems running once its going, and still very responsive.......

 

[Glyn]

Don't rule out the O2 sensors just because you don't have all the symptoms in the pelican write up as all symptoms are rarely displayed, however, the Durametric reader doesn't just identify a failed O2 sensor but also reports a "ageing sensor" - this is when outputs fluctuate just a tad out of tolerance - so you could still find an issue with them, and remember your car will have 4 of them (some cars dependant on model and year only have two)

Oh yes, I forgot to mention - there are no chokes on modern cars. The choke was a flap that restricted air and therefore richened the mixture up, modern cars all use sensors and add more fuel rather than less air.

I assume you have checked the electrical connections to the O2 sensors and the water temperature sensor because a poor contact or broken wire/ electrical plug loose would be picked up by a code reader that the sensor is unserviceable, it cant distinguish between an out of tolerance reading with a no reading at all

 

[dext986]

So, hooked it up to a reader and no codes found.....
unless i took it to Porsche and they charge me a fortune and hook it up to some all singing and dancing thing I am at a bit of a loss...