notthd

Hey all,
Having an interesting morning. Pulling out of the drive way the engine bay made a poof of smoke (I have hood vents for turbo heat here in Az - aftermarket) and it rolled out of the hood vents then into the cabin. Not sure of the smell or just exhaust but no Antifreeze or coolant flavor to it. Then within seconds the motor died and it will not restart. No leaks from under and nothing looks out of place.

Any ideas out there as to what to look at first. It just turns over with no kick to it whatsoever. No noises, rattles, knocks etc and has been running perfectly. Does have 143K miles on her but no issues till today.

Snide or comedic comments encouraged, I could use them at the moment.

Cheers, Mike

phatz

Time to push it over to Sean Murtha

BobcatBrian

Scan for codes and report findings.

notthd

From the West side that's a long push LOL.

Only code registered was P2310 "D" primary control circuit high
I cleared it and tried to start and same thing. Turns over continuously until I shut off the ignition. Not sure that is normal. Once the starter is engaged it will keep turning over even with the key in Run position. Seems strange but OK.

All I know so far. Thoughts ?.

95_993

Is look around to see if the was a small wiring issue. A major short could cause the puff of smoke and some fried insulation and burned harness somewhere

Rodents have a tendency to check on things

BobcatBrian

Does the tach needle move or bounce when you’re cranking?

TRINITONY

crank position señsor, just a thought

notthd

I thought of the crank positioner also. Have'nt had time to check on it yet and figure out how to test it.

Some odd things that may be related. I off road my Cayenne and during a 70degree hill climb (yes almost straight up) I lost throttle. It would still idle but had no pedal. Once back on level ground problem disappeared. 1/2 tank of fuel when it occurred. Recently I had misfires occurring. I replaced coils and issue went away. A couple of months later I am getting "running to lean" codes intermittently on both banks. Keeps occurring but not constantly. Car runs or did run perfect. Wondering now if I had a fuel pump issue in one or now both.

Hummmmm????
Cheers, Mike

notthd

It doesn't bounce but after a second or two it moves off zero up to 500rpm while cranking and stays there until I stop the starter. Crank sensor most likely is working correct?

thesteve

Sounds like what I experienced when my first attempt at repairing this tube with regular heat shrink tubing failed (see link below).
The tube blew open and produced a puff of smoke. Then it wouldn't start again.

https://rennlist.com/forums/cayenne-...-tubing-2.html

Oh, forgot to mention, after using the proper high-temp, clear heat shrink, I eventually had to replace the crankshaft position sensor for intermittent no-starts.

Petza914

This. When cranking the tach needle should jump up and down a little as it senses engine rotation. If it doesn't know where the crank is, it won't fire the spark or fuel.

My guess is the CPS failed, you got a backfire back through the intake from a mistimed fuel r spark pulse and now it can't see engine rotation.

You should also check the airboxes and filters to make sure nothing was damaged if it was a backfire.

notthd

All good stuff, thank you. I will get to look at it in more detail tomorrow.

Cheers Mike

oldskewel

On this specific clue, minor comment ...
Not sure what kind of car you've got there, but on my 2004 S when I was doing a compression test during my PPI, I found that the engine cranking would automatically stop after an exact amount of time (or maybe revs?), like about 10 seconds (i.e., even with the key still held all the way to START, it would stop cranking after 10 seconds). This was useful for repeatability in making good compression measurements. But anyway, for you, the fact that this feature to stop cranking seems to be gone might be a clue.

Other than that, I'm thinking some sort of CPS failure makes sense. Going all the way back to the sudden death and puff of smoke - maybe CPS failure caused a cylinder firing at completely wrong phase, sending smoke back out the intake.

Putting those together, if the stop-cranking code counts revs rather than time, and the CPS means it can't count revs, that would explain what you're seeing.

notthd

Totally agree. I was unaware of the time out in cranking. It makes perfect sense that if the car does not have a solid CPS it doesn't time out so to speak. Counts total vs. duration seems logical related to the starter. The smoke also explained if it failed and backfired.

I ordered a new CPS for first attempt. Amazons for $14 bucks arrives today to troubleshoot and Bosch for Pelican parts arrives tommorrow. Hopefuly I can at least get it out of the street. My drive is narrow and slightly uphill. Welcome to Phoenix suburbia.. It is a 09TT. Thanks for the insight.

Cheers, Mike

BrianC72gt

So, thinking about a common point of failure that would take out all cylinders and won't throw a code, my wild assed guess is the high pressure fuel pump. Or it could be the low side pumps. At 143k, your low pressure pumps (in the tank) are beyond past due for change out. Is there a banjo bolt to access the low side and the back of the engine bay? I vaguely recall a simple inline disconnect joint on my 04TT (old school manifold mounted port injectors). There are two fuses (again in an 04) under hood in the cowl area...fuse numbers 13 & 14 in 957 (confirm which ones) .. that power the two pumps in the saddlebag tank under the back seats. Test the output of each pump by pulling one fuse, then put it back and pull the other. When mine died, one was completely dead and the other started going intermittent.

I don't know what code(s), if any, a failure of the high-pressure pump would throw.

Edit - I like the previously suggested emissions hose from the check valves to the intake manifold. The rupture would explain the puff of smoke and the break allows unmetered air which makes starting a challenge. You can remove the ends from the broken pipe and use some reinforced PCV rated hose. I did mine with reinforced silicone hose and hose clamps.

Happy sleuthing,

Brian