986 Forum - The Community for Porsche Boxster & Cayman Owners - View Single Post - Annoying cold start problem on a 1997 2.5 Boxster

poortmanc · 12-24-2019, 04:33 AM

Looks like it was the throttle position sensor (TPS) which was giving wrong values on the first percentages of throttle in combination with a loose AOS hose on the bottom.

This explains why after every reset the car ran more or less fine (default settings) - and became worse the more kilometers I made.

Idle hunts still a little bit on a cold start, but not stalling any more (hunting between 700-1100 RPM and quickly settling). Fuel trim on the long term is still a bit off, but becoming better the more I drive.

Bank 1 Long Term: -1.6%
Bank 2 Long Term: -4% (seems like something is not yet correct here)

I'll keep you posted,

Happy holidays.

12-24-2019, 04:33 AM	#8
poortmanc Registered User Join Date: Dec 2019 Location: The Netherlands Posts: 9	Looks like it was the throttle position sensor (TPS) which was giving wrong values on the first percentages of throttle in combination with a loose AOS hose on the bottom. This explains why after every reset the car ran more or less fine (default settings) - and became worse the more kilometers I made. Idle hunts still a little bit on a cold start, but not stalling any more (hunting between 700-1100 RPM and quickly settling). Fuel trim on the long term is still a bit off, but becoming better the more I drive. Bank 1 Long Term: -1.6% Bank 2 Long Term: -4% (seems like something is not yet correct here) I'll keep you posted, Happy holidays.