Mountain Driving - Boxster Won't Start!

[Dlirium]

Hi All - I'd appreciate some direction here -

Took a nice drive up to Tahoe over the weekend, got to about 4000 feet going up hwy 88 and pulled over to check out the view. Got back in my 2000 S with 122k miles that has been running beautifully, and got the "crank - not start" thing.

I waited about 10 minutes and tried again - same thing. Waited another 45 min and tried. Still no joy. At that point I decided to cut my losses and call AAA. They took it the 170 miles to my house while I got a rental car and finished my vacation.

When I got home Sunday afternoon, i went out to the car (crossing my fingers), and sure enough, it started right up! So I *think* that rules out what I had initially suspected as the fuel pump.

I've heard it could be the "fuel vent valve" our something, but haven't come across anything definitive. Again, it runs great, so probably not a cam sensor or bad coils.

Anyone have an idea? Sure would be grateful for any tips...

[ccjazz]

Sounds like a possible Crank Position Sensor acting up. They tend to fail when hot and work again after the engine has cooled. Search here for CPS and there are numerous threads / repair diy's.

Here is one of the threads:

"Help"

[rick3000]

Most likely a failing CPS sensor, for the reasons mentioned by ccjazz.

[911monty]

When cranking if the tach doesn't move then CPS likely. Another item that can exhibit this type behavior is the fuel pump relay. They are cheap and easy to replace and is the first thing I'd change.

[Disaster]

Heat and altitude. Vapor lock? Next time try loosening the gas cap.

[Dlirium]

Originally Posted by Disaster

Heat and altitude. Vapor lock? Next time try loosening the gas cap.

Huh! I thought Vapor lock was a thing of the past! I'll try...thx!

[Dlirium]

Originally Posted by 911monty

When cranking if the tach doesn't move then CPS likely. Another item that can exhibit this type behavior is the fuel pump relay. They are cheap and easy to replace and is the first thing I'd change.

Good thinking Monty - I might as well do that one too!

[Dlirium]

Originally Posted by ccjazz

Sounds like a possible Crank Position Sensor acting up. They tend to fail when hot and work again after the engine has cooled. Search here for CPS and there are numerous threads / repair diy's.

Here is one of the threads:

"Help"

Thanks Rick and Jazz - will check it out for sure!

[Disaster]

Originally Posted by Dlirium

Huh! I thought Vapor lock was a thing of the past! I'll try...thx!

Fuel injection and submerged fuel pumps got rid of most of the problem which was caused by the fuel literally boiling in the lines but there can still be issues in the fuel delivery system especially if it isn't venting properly.

[kk2002s]

I have felt this pain because of fuel pump relay. Hard to replicate as they heat up and then stop working so you need to get it to that state to jumper to test.
Not an expensive part so not a bad idea to have a extra on hand

[azlvr]

Had the same problem it was the CPS.

[Most_Wanted]

CPS seems right. This happened to me a few months back. Driving calaveras/felter/sierra. Stopped at the shell station after the long downhill strait. When i went to restart i had a no crank issue. luckily it only lasted for a few minutes.

[kirkandorules]

There's nothing funny about vapor lock

[Dlirium]

OK, Again - thanks to all that commented. I replaced the Crankcase Position Sensor as well as the fuel pump relay. Good news is that it fired right up! I haven't taken it on an extensive trip yet, but so far, so good!!

[Nine8Six]

"VaporLock" - Sounds like a Rock Band

Guess you've done that already but just in case... have you scanned for fault codes? Erase them and see if they come back, etc?