Hello,
i've got a 99 t6. A little background, it has 115k miles, bought it at 86 and i don't know if the throttle body has been serviced/replaced before i got it.
here's the problem:
in the mornings (but usually anytime the engine is cold), when i give it gas (not flooring, just regular) the car dosent' move, then all of a sudden the rpms shoot up to 2500, then immedietly drop down to 500, then back up to 2500 and so forth. It does all this with the gas pedal in the same postion. once the engine is warm it runs ok, but untill then the morning are horrible.
has anyone been through anyhting simillar? Could it be an issue with the thorottle body?
any help would be appriciated,
thanks, veso

 

I would definately say the throttle body is at fault. Do you have a check engine light?

 

ya it comes on sometimes. i have an obd scanner, it pulls up a code about a large emissions leak. Most of the time i just erase it and then it comes back in a few days. Sometimes while im driving i also get a text message that my fuel cap is loose or open, then it goes away...
thanks

 

Could be a problem with your EVAP system that pulls the vapors from the fuel tank into the intake to be burnt. This could cause the message for fuel cap and the emissions code. The vacuum leak could contribute to rough idling and surging, but not the symptoms you have described. I would get someone to hook up a real time OBD scan tool to it when it is cold and see what kind of data you are getting from the sensors. This may help in narrowing down the problem.

 

mine pulls real time data. which sensors should i look for? My dad is a mechanic but he's out of the country for a long time and this probelm is bugging me A LOT! Thanks for your help

 

You may have to speak to a mechanic about what to look for. I know the o2 sensors will give you an idea if it is running rich/lean. You need to find out what range each of the sensors are supposed to be in and find the one that is out of range or close to it. I just got the service records from my 2001 S80T6 had the charcoal canester replaced at around 50000 miles, so maybe you could look there. That would cause errors in the evap.