Mike Murphy

+1.

Bruce In Philly

I am not convinced the engine was flooded.... just don't believe it. It had to have been something else.

Peace
Bruce in Philly (now Atlanta)

ADias

Where did you get that info for an ECU controlled Porsche engine?

jchapura

So, is there a consensus (or owner's manual reference, PIWIS reference, etc.) for the procedure to clear a flooded engine on a 997.1?

The reason I ask is that it has happened to me. After filling the gas tank up at a gas station, it cranked but wouldn't start. I smelled fuel at the exhaust tips. I reverted to the old "carburetor"-based method (I just didn't know what else to try) and held the gas pedal down and cranked for a few dozen of seconds and the engine sputtered to life.

ADias

It may not have been flooded... it could have been an airlock.

Busta Rib

Agreed. Our cars are drive-by-wire. The ECU controls everything and I think the Porsche engineers would design the car to prevent flooding. This is an antiquated outcome from the old carb and mechanical throttle and gas pedal days. Based on the OPs symptoms, it points to low/dead battery to me. Simple as that.

Bruce In Philly

I've been doing the Google dance and am finding that DFI engines can flood... but it appears they flood when something else is wrong, such as drippy fuel injectors (faulty), or... hold on... a bad battery. I really don't know how a bad battery can cause flooding as the computer should handle such a situation... of course, I can make something up like the engine turns with no spark... but again, I never saw that. When a battery goes, it won't turn the engine over in my experience. These sources on the 'net are not what I would call credible either so....

Anywho....

I still stick by my suspicion that there is something else going on. Flooding in a DFI engine... well this was the first I ever heard of it. Since I got married, I now realize that I am wrong way more than I am right if ever, so I can take it. But I just don't believe it.

Peace
Bruce in Philly (now Atlanta)

Mike Murphy

I’ve seen this happen multiple times on older vehicles. Low battery voltage results in low voltage at the spark plug, because a coil is just a transformer. The voltage on the input side is directly related to the voltage on the output side, which can result in not enough to actually create spark across the gap.

Higher end racing ignition systems have electronics that can overcome this issue.

docdrs

I said almost universal just in case it is not so in all engines. There are many reasons and ways to fuel flood an engine. Some manuals state , fully depressing the throttle on tb, mpi, and di engines will generally cut power to the fuel pump and allow balancing of the air fuel mixture to allow for combustion. It also occurs if the transmission is not in neutral. Very simple to put these fail safes into ecm programming. If you want to verify, try and start your car with throttle fully depressed, but don’t let off the throttle if you hear it fire a little or it will start as you have changed the conditions. Theoretically if your injectors are not leaking there should be no firing of the engine. If your injectors are leaking ( after engine shut down ) the engine may briefly fire. The Germans may have programmed their ecm’s differently from most not because the shouldn’t but because they can. Take this fwiw and not gospel as we should never assume everything is the same, and I am bored at the moment to write all this. Merry Christmas to all

Bruce In Philly

I love learning stuff. Thanx. I will apply this to Her lexus when it floods. It has a single injector and will flood if you start and then turn it off right away. The lexus forms say to just keep cranking until it fires, but this sounds way better. Plenty of stories of flat bedded cars to dealerships for this issue.

Peace
Bruce in Philly (now Atlanta)

Wayne Smith

I've found a few things on a quick search. Look at post 8 ...

https://www.ford-trucks.com/forums/1...-cranking.html

But is this universal? Software is so easy to change that determining this could be like deciding what Ford master cylinder to order for a customer's car before he brings it in ... these can vary not only by the month, but the week, day, and hour of manufacture!!!!

rsalicrup

Don’t think it was flooded. Newer cars don’t flood like carbureted cars. Even when my M3 had an injector stuck open, it started…ran like crap but started. I would definitely look more into this to make sure you don’t have a stuck injector because that can make things a lot worst. Best way to diagnose is to let the car sit for a bit, pull all spark plugs and pull fuel pump fuse. Crank engine and see if/or how much fuel comes out. A small spray is okay since there will be residual fuel in the lines.

user 9089299

I wanted to do a brief update.

I noticed a coolant leak shortly after.

AOS was leaking coolant.

here’s the work I did to make the car perfect. Don’t know what caused the issue, but I’m thinking it was the AOS leaking.

I changed AOS
coolant tank (it was easy to remove without dropping engine with the things I had to take out to get to AOS)
coolant pipe under driver side (the plastic part)

then I had no leaks great! But misfire during idle. So I research MAF gets dirty if AOS fails. Cleaned MAF. Car is perfect now