I have a '99 Forester that when exposed to uphill climbs, like going up a mountain, fails to start when parked after reaching the top. If I walk away and come back 15 or 20 minutes later it starts right away. I assumed this was caused by heating so I replaced both the cam shaft and crank shaft sensors and it still does the same thing. Has anyone ever had an expierence like this?

 

Heating issues = cam and crank sensors?

Hmm.

I'd probably be checking the coolant levels, make sure that you don't have carbon smell in your overflow tank (sign of head gasket issues).

 

Fluid levels are OK. Head gasket problem should not cause the car to not start. Thanks for your response.

This has to be a problem with something heating up, like maybe a crack in a sensor or something. I've had experience with a crank position sensor having a crack in it, which caused the same effect. When the crank sensor heated up the crack would expand causing the car not to start untill it cooled. This car has a new crank and cam sensor so that can not be the problem. What about a bad knock sensor? Can it cause problems similar to this?

 

You might get more exposure for your problem over at www.subaruforester.org.