Hot issue

[bugman]

I wandered if this was the case, I may be wrong here, but doesn't the ICV then open when you release the throttle which sort of negates this answer (the Throttle body is completely closed by the butterfly at idle).

So I then went back in and checked the continuity of the throttle position sensor (all OK).

Should have mentioned that the idle is OK after the 10 - 15 secs of throttle being held open.

Also when intially cranking the engine fires up for a second then dies so I am assuming (probably incorrectly) that the fuel supply rails still have some fuel in them.

I am still suspicious about the ICV but I still suspect that its the fuel supply/ventilation system that's at fault.

Cheers John

[porscherescuer]

Any update on this?

[bugman]

Update on hot start issue.
Sorry for delay in update but have not been home to play with the Boxster for several months.
Anyway replaced the Evaporation Control valve (under the left hand inlet manifold) no chance to check the hot start problem as ambient temp now lower, but still getting the honk from near the filler cap.
BTW its a pig of an assembly to change, one P clip cannot be got at (unless you remove the manifold).
I now suspect that either there is a hole in the evap/fuel filler system somewhere or even a bad seal on the filler cap itself.

[porscherescuer]

Hey Bugman. I have the answer for you. I spent forever trying to fix this issue on my 99. It is the regeneration valve. About $150 part and labor is not too bad. This fixed all of my hot start issues. The part was back ordered, so It must be somewhat common.