i got an s5 t2 that i just put back together i ported the wastegate it won't hold a idle it stalls unless i hold the gas in alittle other than that it runs great all through the rpm range but won't idle do you think if i adjust the idle screw it will idle or is there something wrong with it i am running just a 3'' dp and mid pipe right now until i can get the money for a cat back any help will be appreciated

 

Make sure the hoses on the TID are tight, and that the TID is not a huge air leak. Also check all vacuum lines around the turbo.

Unfortunatly you have complicated things by changing the adjustments. Now you can't really troubleshoot the original problem because you have introduced others.

 

well it ran fine and held a idle before i ported it now it stalls whats the best way to check for vacuum leaks

 

vac leak! or u got some hoses swaped around.

 

a little trick we use in the shop is take a can of brake clean(non-chlorinated), whith the car running lightly spray around all the vacuum lines, the idle should raise if u hit the leak.


now im VERY new to rotories, but i dont see how it would cause a problem(key ingrediant in most brake cleans is "tolulene" which happens to be a DIY octane booster too, some companies use it in their bottled formulas too) so before u try this method, i would confirm it wouldnt cause any probs with somone in the know.


also most vacuum leaks will sound roughly like an intake hiss while the care is running.

 

would just running a 3'' downpipe be the problem due to no back pressure

 

And why would reduced backpressure cause an idle problem? That's just silly...

This has nothing to do with the exhaust or the ported wastegate. Like Aaron said, something has not be reinstalled properly, and is causing a vac leak.