Hi, my 2006 JCW doesn't like restarting if it hasn't been driven far ( eg taken out of the garage and parked up). Will start first time but not on all cylinders for a few seconds.

I'm guessing the super rich JCW map fouls the colder plugs and this is normal? anyone else experience this?

 

You need to use NGK iridium spark plugs # BKR6EIX This is important!!!
Also, you may need a fuel filter and a pressure test for fuel pressure, to make sure it is getting enough.
If it smokes black, when you start. I may be due to leaky shot injectors.

 

Starts perfectly in all other scenarios so likely isn't fuel pressure related. Time between restarts doesn't make a difference either, just distance travelled on previous run.

Will check plugs, possibly these are original as it's only done 40,000 miles.

 

The factory plugs are NGK, but inferior, as the price is a lot higher on the best plugs. The ones I listed are great!
You may also want to use elctric cleaner on the primary plug on the coil. Also check to make sure the battery is putting at least 12.4 before trying to start. There may also be a loose battery lead.

 

Currently has NGK R - BKR7EQUP plugs which I assume are original. Service interval is stated as 100,000 miles and the car has only done 40,000
Might be worth swapping them out anyway, guess I should go for the BKR7EIX to match the heat rating of the OEM plugs for the JCW? Or should I move to BKR6EIX?

 

Even though plugs can last that long, when you change them out, you can really notice a difference, even at 50K miles!
I use the 6's and I have a factory JCW 06 R53. No ping, no sputter and no knock! (BKR6EIX)

 

I haven't posted in a while as the problem went away... However it has now returned. I put new plugs in on Friday and the problem remains.

I checked and cleaned the coil terminals and wire plugs as well as the connector to the coil pack...no change.

Battery voltage appears a little low...but this could be the my old voltmeter. I say this as the car cranks fine and the reading matches that if our other car. But still I want to rule the battery out.

Is it possible (and safe) to disconnect the alternator and run the car? My theory is perhaps the voltage is boarder line for the coil pack and only gets high enough once the alternator is supplying a high enough voltage across the battery.

 

Just did a hard start on a R53 and on this one the scenario sounds the same as yours. Turns out the fuel pressure regulator was leaking internally. The leaked fuel was sucked up by the vac line and into the manifold creating a rich condition. Aside from pulling the vacuum line off the FPR and seeing it was wet inside while removing the intercooler I could smell fuel from the left side horn. Maybe worth a look.

 

Thanks for posting. Stripped the intercooler and manifold down and checked the vacuum line as suggested. Unfortunately everything looked perfectly fine, no cracks or fuel in the intake.

I did finally find the issue. Despite the voltage checking ok, the car cranking ok and the battery status window (colored circular window) checking out ok the battery was the issue. Turns out it was the original battery dated 2006. Swapped it out and the problem hasn't returned.