Up Next – Coil Packs and Spark Plugs

Aston Martin DB9 Coil Pack
DB9 Coil Pack

Been travelling (with work for about 8 weeks now) and looking forward to getting back to home and some R&R time (which for me means fiddling with something on the DB9).

I’ve had a lumpy misfire at idle since I purchased the car, but it used to be very, very minor.  A few months back it started to become much more noticeable and it’s time to deal with it.

Misfire Profile Correction LearnedAvid readers of the blog may have figured out I was heading in this direction already by my posts about the OBDII reader and finding information about misfires, etc.    What’s I’ve learned with my car is that I have 2 cylinders misfiring substantially.    I have also been doing my research about previous service history (which you can see in the My Car section of the blog) and I learned that the DPO (damn previous owner) serviced just ONE of the coil packs prior to selling me the car, and the dealer had a footnote about other cylinders showing misfires, but they deemed it not worth the expense to fix it then.  So now its my problem.

A lumpy idle / misfire is a common problem with early DB9’s and is an issue with weak coil packs.  I think I’ve heard people say that if your car is over 10yrs old or 20K miles or more, the issue will appear.  It’s even mentioned as typical issue by Grant Neal in his excellent book The Definitive Guide to the new Gaydon era Aston Martin – A Buyer’s Guide and Car Enthusiast’s Guide (check out my blog article on this book)

This July 4th long weekend I am all set to change all 12 coil packs and spark plugs.  Parts ordered and arrived.   Process researched and vague ideas in place.  Special tools ordered and delivered.  GoPro charged and ready!

Over the next several weeks I’ll be starting to publish the process in both written blog and video format.  As usual I will be breaking it down into bite size chunks matching the sequence of tasks to get it done, usually 2-5 mins of video at a time.

Send along you tips and advice.   Here we go…..