changed oil, installed 997 shifter, now car won't start

[JasonStern]

1999 Porsche Carrera 2, 18.6k miles.

Drained the old oil and replaced it with a new filter. Cut the old filter in half and ran a magnet through it to ensure no metal shavings. Replaced the oil with Motul 5W-40, filled to the top of the dipstick. Car started up just fine. I let it idle for 30 seconds to ensure no leaks, then drove it around the block - no weird sounds, no leaks.

Parked the car in the driveway - slight incline if that matters. Installed the 997 shifter. Rolled the car down into the street a bit so that the car was level. Checked the oil. It was on the low end of the dipstick range, so I filled it close to the top. I verified the level was good with the electric oil level gauge. But then when I tried to start the car.. nothing.

The motor turned freely, and at first it sounds like it wants to start, but then as you continue to crank, there is less audible sound like the motor is catching. The engine builds oil pressure as the starter turns the motor. I plugged my Durametric in - no error codes. I replaced the battery with a newer, known good one from my Boxster, waiting 15+ minutes. No help. I checked the engine related fuses - they're all solid.

Anyone have any ideas on what could be wrong or how I should continue trying to diagnose the problem? I am running out of ideas as I cannot think of any problem caused by an oil change or the short shift kit installation. Thank you!

[therock88]

Not sure here, but just based on your story, I do not think it has anything to do with your oil change. I am guessing when you changed the shifter you have an issue there. If it is detecting/thinking it is in gear etc, it will likely keep it from starting. I would start by going through all you touched there and ensuring neutral switch and all other connections are replaced properly.

At least that is where I would start. There are others on here that likely know a lot more about your specific problem than I do.

Good luck!

DC

Edited February 17, 2013 by therock88

[Ahsai]

I think you need to verify both spark and fuel supply. You can pull one spark plug to check spark. You can also jump the fuel pump realy to verify the pump is working. I can think of at least two possibilities: fuel pump and crank sensor.

Agree with DC that can't think of anything related to your oil change and shifter mod.

Edited February 17, 2013 by Ahsai

[JasonStern]

Thank you both for the ideas.

I don't think it has anything to do with a neutral switch, as I believe the neutral switch on the transmission is only for tiptronic cars. Mine has a manual transmission, and the switch that detects whether or not the clutch is depressed appears to be working as the starter is engaging and the motor is turning over.

I do believe the fuel system is working, as I can hear what I believe to be the fuel pump priming when I turn the ignition to the on position, and when the motor turns over, I can smell unburnt gasoline fumes in the exhaust.

I will try to verify spark tomorrow, as the car inconveniently won't start outside in the cold instead of inside my garage... which is also cold.

Agree with DC that can't think of anything related to your oil change and shifter mod.

Thank you for explicitly saying this, as my girl was getting on my case about doing my own maintenance and minor modifications. (So you're saying it worked great, and then you installed some short shift kit you didn't need, and now it's broken?) <_<

[Ahsai]

Jason, couple more ideas:

1) I forgot when the immobilizer is actived, whether the car will still let the engine crank but not fire. Do you have another key to try?

2) any possibility of water in your fuel system. e.g., any rain recently when you fill up? Someone recently drained out like a pint of water from the fuel filter after he filled up the car and it died at the gas station. Somehow rain water got into the underground gas tank.

[JasonStern]

Good news. When I went to go check for spark, check the fuel, etc. this afternoon, the car started. It idled rough, but it started. I drove it around a bit and filled the car with fresh gas from a different gas station, and it seems to be running fine now. As a result, I think there might be something to the bad/contaminated gas idea. It's either that or the Carrera being jealous that I drove the Boxster. ;)

As a precaution, I will change the fuel filter. While the filter doesn't have that many miles on it, it is still fourteen years old.

Thank you, everyone, for the help.

[Ahsai]

Glad to hear that you got your problem resolved w/o much effort :) Also good call to change the fuel filter due to age.