Ok so I have an 08 GSR with full bolt ons, cams, injectors & such....my car has been running like absolute ****....some times it idles & the AFR is at 10.0-11.0 sometimes it idles at 15.0-16.0. Also at cruising speeds the air fuels will fluctuate between 10.0-11.0 & sometimes they will be at 14.0-16.0. Why the fluctuation? I know at idle its supposed to be lean and same with cruising.

Under WOT in any gear my air fuel immediately drops to 10.0 possibly richer since the guage only goes to 10.0 & it falls on its face. With the cold weather it is also holding more boost....could the car be compensating? Car just doesnt feel as fast as it was over the summer & now that its cold out it should be even faster. Any thoughts you guys have? I had my tune adjusted about a wk or so ago b/c i was hitting boost cut off so they adjusted the tables.

While driving if I do a pull from 1st to say 4th....should my air fuel start off at 10.0 than taper off to 11.5 or so....the reason i ask this is b/c the taper doesnt occur until the higher RPMS say 5k-6k AFR is a steady 10.0 until than & i feel like there is more power to be had based on other peoples dynos & seeing AFR's of 11.5 @3K meanwhile im at 10.0 Hit me with some feedback please.

Thanks

 

Don't worry about cruising and idle AFR's as your car will primarily be in closed loop, targeting 14.7 afr. During transitions between open/closed loop, you will see fluctuations. What you should be most worried about is your AFR at WOT. It sounds like it's way off, and you need a better tuner. At WOT, your AFR should be between 10.5-11.5 depending on rpm and tuner preferences (roughly speaking). Your long term fuel trims might be off, causing your tune to go way too rich. If your tuner just recently adjusted tables, they should have checked LTFT and AFR's after making adjustments. It sounds like they didn't.

 

Ill have to inquire, there an awesome shop so im sure they wouldnt mind taking a peak its just weird how one moment the car will run good & the air fuels will be solid but than all the sudden its like the map changed & air fuels are way off.

 

boost leak... pressure test the whole system

boost leak will cause high load (which will cause your boost cut)
boost leak will cause rich WOT condition (since metered air isn't making it into the engine)
boost leak can affect trims (since air is being gained/lost before the engine)

 

Im gonna go over all my pipes and probably re install everything to be sure. Check all the vacumm lines hopefully its something stupid like a small leak & not the tune.

 

Just be aware that some people are having issues with pressurizing the pipes with more than ~15 psi if you are thinking about a boost leak test. I think the seals in the turbo are getting dislodged and are letting oil through to the exhaust side and causing spy hunter smoke shows.

Seems like a tuning issue if you say it leans out to more normal AFR's at WOT and higher RPM's. Verify your LTFT is closer to +-2 of being 0 and see if they can adjust the AFR's to 11-11.5 AFR range more consistantly.

 

ya ill check it all out hope for the best....too damn cold tho!!!