i have been told by the previous owner that i have a bad turbo-downpipe gasket, and the exhaust leak is very loud sometimes. i have been having problems with fuel cut ever since i first test drove the car (88t2) but after i replaced a few actuator hoses the problem seemed to be fixed. but after driving the car a few more times under hard boost the car starts hesitating again. this happens even when the car is totally warmed up, and the rpms dont seem to matter. it doesnt seem to be as hard as fuel cut (although i rarely drive the car so i dont really remmeber what the intial feeling of fuel cut was like), but im thinking that the leak is causing the turbo to boost too much and is leading to fuel cut.
what do you guys think? is this possible?

 

Have you tried an aftermarket boost gauge to see what your true boost level is at??? Or maybe a fuel cut defencer... but if you have boost creep, then hard driving probably isnt the most intelligant thing to do, especially when hitting fuel cut, or if your fuel system is stock youll most likely run into lean problems. The nock off gauges seem to work and are alot cheaper. Look on ebay too.

my 2 pennies

 

I'd find it hard to believe an exhaust leak raising boost signifigantly...
get a multimeter onto the pressure sensor ouput while driving, (easiest at the ecu) and confirm the sensor is at 3.65 when the car hesitates. if not, then you've got some other variety of hesitation problem.

 

Does this happen in every gear, or mostly 3rd, 4th?

 

thanks for the replies guys, i just bought a boost gauge tonight. the problem mostly occurs in 3rd and 4th. it might have happened in 1st and 2nd once or twice. im not really sure. im scared to rev high and once i feel or hear something out of the ordinary i immediately back off. ill look into checking the pressure sensor. what is the significance of 3.65?

 

3.65 is the level where fuel cut occurs... but if you've got a half decent boost gauge you should be able to see easily enough from that if you're reaching around 8psi-ish.

 

When you get a boost gauge and if it shows boost within safe limits, check for a stuck or even cracked seal. This condition would not necessarily show up on a compression test, but under boost, especially 3rd and 4th gears, the compression is passed to the following chamber, and you experience kick back. You could probably take the car to 80/90 moh if you feather the accelerator, and don't hit a lot of boost, and have no problems. Just a thought.

 

i hate being an exhaust leak