mine was dropping into the 9's last weekend on the rollers as well as slightly missing on idle
will hopefully know whats up with it this weekend...
the suggestions on mine so far are o2 sensor, vac/boost leak, knackered ring or a valve not sealing properly
Thats crazy AFR's .. are they to be believed,? to be honest I'd have thought not..
it looks at the beginning of the plot to be on and off the throttle coasting (the massive lean peaks, so lean its hard to believe any petrols be burnt AFR of 18, thats the sort of figue I get when i've lifted off and the engines acting like an air pump) then dropping off the scale on boost rich, lower than 10, if its true lower than 10 you'd be kicking out black smoke.
Thats not good.
Blocked injector giving really poor spray pattern, blocked fuel fliter, or dragging air in somewhere although on a rev3 the MAP sensor should cope with that. Is it missfiring at all when coming on boost?
I don't know about stock ECU's but if its open loop O2 then the lambda sensor maybe shot / giving an intermittant signal.
If you were not seeing black smoke then a hole in the exhaust could give the high AFRs
You don't have any bodge it electronics, no resistor mods?
to be honest the car runs sweet, fires up idel's perfect on wide open throttle it holds boost nice and smooth untill redline, i was just a bit shocked at seeing the readings myself.
tested the o2 sensor and its fine on mine.
also swapped map sensors to see if that was knackered, but its fine aswell.
mine doesnt seem to be missing and cant hear any vac leaks. so it's gonna have a leakdown & compression test done next...
i'm going to cable tie all the hoses/vac tubing incase its a boost leak i have, i'm also unsure if the bov is leaking (2nd hand, not the correct screw so it's been apart before), so have ordered a new one to see if its that.
mines only kicking out black smoke and a bit of blue when it hits the limiter, the same as most other 2's i've seen on the dyno
it's also ticking over at 700-750 rpm without the lights on & about 900rpm with the lights on, so about 100rpm lower than normal
dyno run --> http://s18.photobucket.com/albums/b149/ ... V00002.flv
making peak torque at 4300 rpm - 5-5200rpm on my old 2. peak power was at 7300rpm, 7000rpm on my old 2.
so somethings going on in the midrange, approx 40lbft & 17rwhp down on my old 2 with the same mods + a PP i/c