It had now been a few weeks since the car was registered and we had started the process of running the car in and troubleshooting.
The first problem encountered was that the spark plugs were fouling after 20 or 30 miles.
At first I experimented with different plugs with different heat ratings but to no avail.
Despite the issue we managed to get to the Simply Porsche event at Beaulieu as it was within range of a spark plug change.
As we spluttered into the grounds I was hoping for a chance to quickly park up as the car was running only on four cylinders.
Luckily ( or unluckily ) we were singled out to park in the Arena parking, which meant having to slowly follow an official on foot for what seemed an eternity to our parking spot. Long before we got to our spot the engine died but fortunately the route was downhill so we could coast most of the way much to the amusement of the official . We were then shown our spot and I quickly started the car reversed it in as quickly as I could where it promptly coughed and died again. We quickly abandoned the car to distance ourselves from the woeful entrance much to the annoyance of the Macan owner in the next space ( who had to realign his car to even out the untidiness our presence had brought to the event ).
Over the next week or so I would go for a run and check / change the plugs on return and lean out the mixture a little.
After a number of iterations we got to the point whereby four of the plugs seemed OK but two consistently fouled - cyl 1 and 3.
I wasn't 100% sure whether this was oil fouling and would improve as the engine ran in (or when I changed to a thicker oil) or whether it was a symptom of overfueling.
At this point the car is still running the Millers running in oil which is thinner than the final oil I will be changing to, but as the car has only done 100 miles or so I don't want to change the oil until I know the engine has run in properly. The limit on the Millers oil is 500 miles so I can run on this for some time yet.
I rechecked compression on the engine and all looked good so decided to consider the overfuelling issue.
I removed the injectors from the inlets and rechecked the fuelling.
I found that the fuel lines to cyl 1 and 3 are running about 15-20% higher flow than the others, so have concluded that fuel distributor isn't correctly balanced / calibrated. Now when I rebuilt it many moons ago I was pretty confident it was just about in spec of around 10%.
The Bosch specs that I can find are as follows:-
Setting point 6cc/min: delivery 6.0-6.8 cc/min ( 0 - 13% )
Setting point 40cc/min: delivery 40.0-44.0 cc/min ( 0 - 10% )
Setting point 120cc/min: delivery 120.0-131.0 cc/min ( 0 - 9% )
This points to why I can't get a mixture setting that works for all cylinders - even at the limit of the Bosch spec it might be a bit of a challenge.
So the task at hand was to get my fuel distributor rebuilt and to get each of the cylinders much better matched.
I checked with a UK rebuild specialist but they wanted a 10-12 week turnaround so I decided to rebuild it myself again.
How difficult could it be!