short term fuel trims high at idle and and partial throttle
 

Hi all I recently installed a Jackson racing supercharger kit on my car and a delicious flash and go tune. I have borla uel headers, and am experiencing high stft at idle and partial throttle especially on start up. they start to trend lower to around 8-12 after driving for awhile but are still positive. I have checked the pcv valve, the map sensor orientation and don't believe I have an exhaust leak as I used 2 grimspeed gaskets where the header meets the engine. I am stumped and I cannot get my tune dialed in until I figure this out thanks. its worth noting that the idle and driving feels fine maybe a little on the high side for idle around 900. otherwise the car drives great, id appreciate any ideas or feedback on what went wrong.

A small intake leak will be about 15% STFT, a large one will max it at 29.7 and the car will run like shit.

I've never done a Jackson install but if you went into boost I would make sure the cap and the hose under the throttle body are still attached. Other places beside PCV would be the block nipple under the AC compressor.

thank you for the suggestion I will check those out, is it possible that if the tne he sent me doesn't account for my catless headers it could cause me to run lean at idle?

Also check idle vaccuum.


Engine off manifold pressure should ve 1 bar ie atmospheric


Engine idle should be about 0.3 to 0.4 bar if its closer to 1 bar you likely have intake leak or bov leak

Idle vacuum should be like -10 psi right? If it's sometimes weaker, like at -7 psi, is that normal?

Yeah -7 seems a bit low