sbefar01

ONLY when i start the car for the first 30 sec, sometimes the car stalls out and emits light colored exhaust smoke, not too much. Once I am actually driving the car and even at idle at stop lights etc, the car runs perfectly, very strong. The fact that my startups are a bit rough is a concern, not sure if I just got a bad tank up gas. I am new here but do you guys have any good guesses here before I bring this in to the dealer for a look?? Thanks a lot. (I did have a PPI done before i got my new ride, it was done by a Porsche dealer, they replaced the clutch accumulator).

Datura

What year and model?? My Carrera S never smokes while a friends GT3 does it everytime. Another guys Turbo often has light smoke on cold startup.

theporscheguy

Interesting. Never had that problem with my 996TT. Does this happen on every cold start? There are guys here that will assist.

sbefar01

its an 01' turbo, 50% of the time its a rough start, 10% it stalls out and 10% of startups it will emit light smoke that goes away after 10 seconds.. Smooth sailing after that. Im thinking maybe a vaccume issue, hopefully nothing major.

Macster

Does the check engine light ever come on, flash, even though it may not stay on for just a few seconds after engine start and *after* it goes dark upon engine start?

With no check engine light...

The car is new to you. Do you have info as to when say the plugs, air filter, fuel filter were done?

However, with no check engine light or even any engine misbehavior at other times, my WAG would be a leaking fuel injector.

The engine, at least one maybe more cylinders is flooded upon cold start. The engine can tolerate a bit of excess fuel at this time but too much and the engine can stall.

Has the engine been recently worked on? If so then a vacuum leak might be a possibility but I think the car would manifest a CEL at some point.

An oil analysis might turn up leaking injector sign from a large amount of unburned gasoline in the oil.

If other possible causes are eliminated the injectors can be removed, cleaned and tested, or simply replaced. I've never had to deal with any injector issues (thankfully!) so I do not know what I'd do in your case. If the miles are high and the cost of the remove/clean/test/install vs. just removing/installing new injectors is close I'd just replace the injectors with new ones.

Added: I've been away for a few days and didn't read your other thread until after I posted the above. I believe Kevin is right and the MAF is suspect #1, not the fuel injectors as I suggested could be the cause of the behavior.

Sincerely,

Macster.

Kevin

Your MAF is failing.. The ECU on cold startup is metering air NOT the O2 sensors. This is done because air is being injected into the exhaust port from your airpump. You can hear it running.

The ECU is trying to dump fuel for the cold start similar to a CHOKE. Clearly the ecu is allowing more fuel for the air that is metered.

The oiled K$N has bled oil on the MAF. You can't clean the MAF. You have a oxide that is burnt on to the hot film. A check engine light will usually appear.

NOTE> my opinion is made with the assumption that you do NOT have a intake leak. If you have a leak, you would have this issue and more. CEL will be tripped.

sbefar01

Kevin, u might be right considering I just put the k&n in, and things were fibe before. Is the maf costly to fix? Thx again

Datura

Good luck with the fix. If you go back to OEM filter, let us know the results please.

Kevin

This is where I have helped folks with previous given advice to replace your MAF, Wideband O2's, plugs and coilpacks has dramatically changed the idle, and throttle response.

Sbefar, I sell all the tune up parts. The genuine Bosch MAF is $268.00

sbefar01

I do not have a CEL yet even though i am getting more and more light smoke coming out, looks like i didnt do my homework before buying a filter. The car will be at the dealer tomorrow for new tires anyway so ill have them take a ganders and do the new MAF/filter change accordingly. Hopefully i'll be under $600 by the time im out of the door.

ohioboxster

Keep us posted, I've had three of these cars and I know I've replaced a perfectly good MAF thinking it was the problem. My car was even throwing codes, it ended up being a vacuum leak. This was years ago on my supercharged Boxster.

The TT will smoke on occasion on start up, as with all P-car flat engines. At least the ones I've owned.

sbefar01

Ill let you guys know what happens, maybe the MAF was already on the way out and the kn filter toasted it. Otherwise it might be an injector. My question is: if i do a software upgrade (Softronic etc), do you guys still stick with the paper filter??

SSST

I have one of Kevin's tunes and there is no issue with the stock air box and filter. It's a pretty well designed setup from the factory.

Since you are fairly new here you will learn that Kevin really knows his stuff. If he says the problem is probably A but possibly B, there is a 80%+ chance it is A, and a 95%+ chance it is either A or B.

Don't go chasing rabbits down holes until you have eliminated his suggestions. Just my .02

sbefar01

Oh i am def with Kevin on this one, if the paper filter gets the job done well then ill stick with it even if I get a tune, ill just confirm its the MAF at the dealer with my current situation.

sbefar01

I just got back from the Porsche dealer: They found no fault codes or startup issues other than a slightly rough idle. I had them go in and inspect the MAF anyways and they informed it was very clean . . . although they said the way it was sitting was a little bit off so they made an adjustment, hopefully the issue wont come back but they didnt sound concerned it was anything major They test drove and hit full boost and there were no leaks either. Maybe an injector still but time will tell . . .