Intermittent hard start with backfire

VASSZ

MEMBER
2006 PORSCHE CAYMAN
4.0L
6 CYL
2WD
MANUAL
90,000 MILES

Happening more and more frequent now.
cranks but won't start. After you keep trying, it backfires.
sends a p0339 code which is crank sensor.
changed it but same problem.

Monday, October 5th, 2020 AT 3:53 AM

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

Have you replaced the crank sensor? More then likely this is starting to fail. If not then we have a connector or wiring issue. However, due to it being intermittent this sounds like a contact issue in either the sensor or the connector.

Let's start with this and go from there.

https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor

Image (Click to make bigger)