Mallone
Silverstone
- Joined
- 10 Feb 2017
- Messages
- 135
Thought I'd update this for anyone who has similar issues in future.
Car went into AMS for a few days for them to diagnose. When Angus plugged it into PIWIS It was showing fault codes for O2 sensors which wouldn't have affected the cold start but I elected to have them replaced anyway. Judging by the pictures he sent through it looked like they had fun changing them!
Over a few days he was able to replicate the problem reliably and after checking all the basics he was able to find a tiny vacuum leak from somewhere at the back of the inlet manifold. Clearly too small to throw up a CEL but wouldn't have been helping. Behaviour was improved but still not perfect.
I'd been getting a a bit suspect about the new (non Bosch) ICV I'd purchased as even when hot I was now getting some weird idle behaviours. Revs 'hanging' at around 1500rpm when coming to a stop, weird fluctuations with revs sometimes 'bouncing' up and down etc.
Bit the bullet and splashed out on a proper Bosch unit and all the problems have completely vanished. My guess is the tired old Bosch ICV (and the cheap Chinese replacement) just couldn't get their act together fast enough at cold start to prevent the revs from dropping after that initial burst of revs. Car now cold starting like a champ and idle behaviour is much, much better all round. Result!
PS. First time dealing with AMS Porsche and a big thumbs up from me. Angus was a top guy to deal with, great comms and super flexible. Recommended.
Car went into AMS for a few days for them to diagnose. When Angus plugged it into PIWIS It was showing fault codes for O2 sensors which wouldn't have affected the cold start but I elected to have them replaced anyway. Judging by the pictures he sent through it looked like they had fun changing them!
Over a few days he was able to replicate the problem reliably and after checking all the basics he was able to find a tiny vacuum leak from somewhere at the back of the inlet manifold. Clearly too small to throw up a CEL but wouldn't have been helping. Behaviour was improved but still not perfect.
I'd been getting a a bit suspect about the new (non Bosch) ICV I'd purchased as even when hot I was now getting some weird idle behaviours. Revs 'hanging' at around 1500rpm when coming to a stop, weird fluctuations with revs sometimes 'bouncing' up and down etc.
Bit the bullet and splashed out on a proper Bosch unit and all the problems have completely vanished. My guess is the tired old Bosch ICV (and the cheap Chinese replacement) just couldn't get their act together fast enough at cold start to prevent the revs from dropping after that initial burst of revs. Car now cold starting like a champ and idle behaviour is much, much better all round. Result!
PS. First time dealing with AMS Porsche and a big thumbs up from me. Angus was a top guy to deal with, great comms and super flexible. Recommended.
