New member here. Got a 2008 Cayenne Turbo that has been sitting for 3 years. Was told it ran when parked. Got asked to take a look at it and get it running. Picked it up and had dead battery. Replaced battery and now turns over and everything seems to work but will not start. I pulled coils and a few have intermitant spark but others have nothing. I didn't check fuel pressure but has fuel to the line on firewall. I put 10 gallon of fresh fuel in it also. I have read forums of starter issues due to leaking coolant pipes under intake,ignition switch issues, steering column issues, and coil pack issues. I moved coil packs from each cylinder and the coil pack seem to all work on the cylinders that have spark but when I move them to the ones that are dead the working coil packs are dead. Crank sensor? Cam sensors? Would like input to lead me in right direction please. I also checked voltage drop when battery is fully charged and voltage drops to around 11 volts when engine is cranking. Plugged it in to code reader and it had every code imaginable in it. From low voltage crank shaft sensor cam sensor fuel pump relay to fuel pump. I cleared the codes and then tried to fire it and still nothing of course. Checked codes again and it came up with a cam sensor bank one code. I then cleared that code and changed the 2 sensors from side to side and still came up with a cam sensor bank one. Could the crank sensor be causing cam sensor bank one to no fire and throw a code? I pulled the crank position sensor last night and ohmed it out. It checked .867 ohms across pin 1 and 2. Im not sure what the resistance is supposed to be on the cks but im going to research that today. Im getting frustrated with this thing but if the cks is good Im thinking about bringing it to the Porsche dealer to figure it out. Any help would be greatly appreciated.

 

I had a problem with the crank sensor on my 04 CS , the crank sensor and cam sensor fault codes showed up together, even though only the crank sensor was faulty.

My problem was intermittent though. She would sometimes crank for along time before starting, and would sometimes stall.

Anyway, my point is , the crank sensor can cause a cam sensor fault code to appear as well.

 

Pull the fuse to the primary fuel pump and try to start with secondary only. Then try it with secondary pulled and use only primary. Fuel pump issues are very common. I'm confused that the coils worked on some cylinders but not others. Be sure you don't see any cracks on the top large coil tubes. VERY common issue. I had a coil pack go out and got 10 different codes, but replacing one coil pack fixed them all. You should test the coil wires to be sure they are sending the spark. Need two people tho, or just crank it with a thick wire in the coil and other to ground where you can see a spark. small gap close to ground. Try to unplug one MAF sensor and try, then the other, then none. I had to run my pig for a day with one MAF sensor, but would not start with the bad one plugged in. Got crank sensor codes with that issue as well. Be sure your throttle body flap is not stuck in carbon build up and do the e-throttle adjust as described in the owners manual. Just turn key to light up the dash and wait like 1 min..cant remember, then release key for 10 sec. A bad vac leak will not let her start as well. check under the throttle body for any cracks or hoses that may have come loose. Check for leaks if you have the tools to pump a small amount of air in. like 5psi? Anyone object? you might hear a vac leak or see if it holds pressure at all and listen. That's what I would suggest to start with. These are tough to diagnose. One thing goes out and tons of codes show up. Might also do compression tests if convenient, but not likely the problem. Hope this helps.