I'll try to make this short. I have had starting / stalling / missing issues lately that are all over the place, and I really need help. Here are symptoms in the order they occurred:
1. CEL began illuminating after car idling for longer periods. Code reported fault in vapor system. Reset CEL and only seemed to return when I would sit idling or after fillups. I did buy a new fuel cap but no help.
2. I opened up throttle on a country road and engine went nuts, missing very harshly and idling low and rough. Engine code indicated cylinder 7 misfire. After a few days and only driving twice, this problem disappeared entirely. Might be unrelated to my worrisome problem, but worth mentioning. I purchased new set of coil packs to install ASAP time permitting.
3. CEL getting more frequent with vapor issue fault. Resets still last longer unless I sit still idling.
4. Now after refueling, very hard to start and misses for a minute or so before smoothing out. Sometimes prompts CEL again with vapor system msg.
5. With about 1/8 tank of gas left, the car stalled sitting at traffic light and had to cycle 3 times before it finally started. Rough running for about a minute. Filled up right after, and was very hard to start again but after a minute ok and no CEL this time.

From some other posts I've seen, some of the same symptoms are caused by low battery, some perhaps fuel pump, still others by some imbalance in vapor pressure system in fuel tank. I should add one more incident that may have contributed. I had to fuel with engine running on one occasion due to low battery because I left my iPad charging by accident and drained the battery. Voltage seems ok at high 13 or low 14v, and battery seems to take charges fine. However, could I have messed up the vapor system when I fueled with engine running?

I'm new to Porsche and not dripping in cash like most, and would really like to get some ideas on where to start, as well as whether these issues are likely related or separate. If a few of you experienced guys would brain storm a bit to help me choose what to check and more importantly, in what order to check which things, I would be very grateful! I realize this may end up being a dealer fix, but I have to try myself first to at least stab at it before buying a new wing for the dealership.

Ideas?

Thanks Folks!

 

Well first, I wouldn't say most here are dripping in cash, I know I'm not.


If you even suspect it could be battery related, drive it to your nearest parts place and have them load test it. Will tell you a lot about the condition of the battery. Cheapest and easiest place to start for sure!!


If that doesn't solve it then you probably need to start getting the actual codes that are being registered with the CEL. That will tell you the most likely direction to go next.


If the gas cap didn't solve the "large evaporative leak" then you might be looking at purge pump or valve. Or fuel pump issues could be the other alternative.


There are quite a few threads and lots of help...


https://www.6speedonline.com/forums/...-solenoid.html


https://www.6speedonline.com/forums/...l-gas-cap.html


https://www.6speedonline.com/forums/...cannister.html


https://www.6speedonline.com/forums/...stem-vent.html

 

Oh, and if charging your ipad drained the battery chances are a load test is gonna tell you to get a new one.

 

Thanks very much for the info, and I'll get started on it Monday! I still haven't found the DIY section yet to look at the charcoal canister and valve replacement, but I'll find it with a bit more diligence on this site. Perhaps I can get this done without the dealer if I can see either a video or read through the DIY steps. Again, thanks for the great guidance!

 

Lots of DIY here.
http://www.pelicanparts.com/techarti...yenne_Tech.htm

 

Do the evap purge valve first. The giveaway was the gas station no-starts...

 

And after checking that, the vacuum hoses on the passenger side by the firewall crack and leak causing some similar symptoms.