997.2 increasingly slow starts
 

About a year ago, my 2009, 997.2, which would always start in about 2-3 turnovers of the engine (~1 second), started to take more cranks before it would fire. That's continued to get longer and after it sits for >5-6 hours it can take 6-7 seconds before it fires, and then it's a rough start, and has stalled a few times. I described this to the dealer and they thought there was a small electrical drop so replaced the battery. I didn't like the idea since there is zero issue with electrical power cranking the starter like a jackhammer. The issue is the engine takes longer and longer to fire and now when it does seems like it could have gotten flooded. I can start it after it stalls but just have to goose the gas a little and rev the engine as soon as it catches.

This is my only car and I drive the heck out of it and now have 85,000 miles but want to keep it forever. Have had it regularly serviced with every suggested interval at the outrageously priced local dealer and they don't seem to have been able to diagnose this issue properly since replacing the battery did nothing for it. Seems like it could be fowled plugs but they've been replaced with the last service and it's not the solution.

I think you may have a problem with your high pressure fuel pump.

Thank you very much for the lead. Once it starts, I wanted to add that it idles fine at about 800 rpm and has no problems whatsoever driving around, or restarting after a short stop. It's only the first start in the morning or when I leave for home at the end of the day that will take 6-7 seconds of cranking before it rumbles to life. Would a faulty fuel pump impact just the cold starts (not necessarily in cold weather) just after it's sat for >6 hours.

Have you tried leaving it at the dealer for the extended period of time and had them start it while connected to PIWIS for analysis? One would imagine they did this in their endeavour to fix it but perhaps not. Make sure they replicate the variables surrounding the issue and do analysis at that time. Might make a difference. If it runs fine when it's been running for a while how could they replicate and find a problem? Drop it off at the end of the day and have them check it out in the morning. 6-7 seconds cranking is excessive. Do you have a OBD scanner? If so what do you get for codes if any.
As far as fouled plugs....they can foul seconds after new ones have been put in but if it catches and drives the plugs will clean up so that shouldn't be your issue.

Thank you very much. I did leave it overnight so they could check it but don't know about how they checked it in the morning. I was reaching out to this forum because I've lost faith in the dealer after spending $800 to replace the battery among other items and wanted to post in case somebody has seen this specific issue before.

Yes it can be frustrating if you don't have any leads/experience. Your basically at the mercy of their efforts. I would think the best test for you would be a fuel pressure test at the fuel injector rails or some similar fuel flow rate test. I say that just because it sounds like a fuel starvation issue if it cranks strong. The spark plugs have no reason to delay sparking. They or the coils should either be failed or good.
Surely your service place (actual Porsche dealer?) has some insight.
The one bright point here for you is that it runs fine once started, so you really have a small problem in my view. Just hope they don't put you through ringer trying to find it. I haven't looked into this specific problem so keep searching....the answer is probably out there or on this site.

oh....and you should ask the dealer what they did.......you paid for it. Make sure they can give you an answer.

Try this. After it has been sitting long enough where you'd experience the problem (overnight), cycle the key to the accessory position where all the dash lights come on, but don't start the car. Turn the key back off and remove it. Wait 15 minutes. Then go start the car the way you normally would and see if it starts faster.

This is interesting and I did as you suggested -cycled the electrical on for about 15-20 seconds, then turned it off and came back 15 minutes later to try starting it for the first time of the day. It started considerably faster but didn't come to life with an instantaneous roar (like it did for it's first 70,000 miles) and instead sort of stumbled to life. I am not a mechanic but the way it came to life reminded me of when an engine is a little flooded and it needs to digest the extra fuel.

Still, it started decisively sooner and probably in 2-3 seconds instead of 6-7. It's not the nearly instantaneous fire-up like it had for most of its life (turn the key.. roar!) where it would fire in like 2-3 turns and less than a second but turning on the electrical first and letting it sit definitely did something.

Dr. what does this tell you?

What we tested there was the fuel pump. That test had you cycle the fuel pump twice to prime the lines before trying to start the car for the first time. Not knowing exactly how the 997.2 fuel system works, it's possible that the fuel pump has an integrated anti-drain back valve that is not maintaining pressure in the lines so when you try to start it, it has to build up enough pressure from zero to start the car.

The next possibility is that the pump itself is only putting out marginal pressure.

The third option is that the injectors are actually leaking so instead of the pressure bleeding out backwards through the fuel pump, it's actually bleeding out forwards into the cylinders. If you say the car starts like it's flooded with gas, this is the most likely scenario and the worst one for the motor as excessive fuel in the cylinders can wash the oil off the walls and fuel isn't a good lubricant. This can be a contributor to scored cylinder bores if it gets bad enough. I would get it looked at sooner rather than later and some of the 9A1 engine gurus on here are recommending preventative injector replacement in the DFI motors every 50,000 miles or so.

Check your Ground Wire off the battery terminal

+1.

very commonly its battery related - dead or dying battery.

Really? If the starter is cranking over strong...how could the battery be the issue?

my apologies, i only paid attention to the thread header and didnt realize the battery was just replaced already.

Go to https://www.nhtsa.gov/recalls , load your vin. Many if not all 09 997.2 had hpfp recalls, campaigns ( https://rennlist.com/forums/997-foru...n-ongoing.html ) or porsche communications. Some even had injector recalls. Might be your lucky day. Per my service records the HPFP was replaced under Campaign WB08 in 9/2011

The ignition switch test for this car is of limited use. There is an electrically driven feed pump in the tank and the hpfp is mechanically driven by the engine.

Consider locating a local porsche specialist to sort it out if the car is not covered by any of the aforementioned possibilities

Wow -cool site, thanks! My VIN didn't get a hit but I'll remember this site for the future!