tuj

What is the stock AFR value at idle (or what range of values does the car typically see)?

zoom44

14.xx warm

tuj

Yeah? I know we run pig rich up high in the rpms, but I thought there was talk that we were running rich sometimes at low rpms/low load/idle to cool the cat?

mysql101

I'm seeing a bouncing idle afr from 14 up to 17 and back. I don't know what could be causing the bounce.

zoom44

befroe the car is warmed up it is not hunting stoich since its in open loop. when its warm and closed loop it hunts stoich at idle

mysql101

What I'm seeing is a bouncing AFR, warmed up and in closed loop. I can also see the AFR bouncing as I drive it down the highway - low rpm, closed loop.

I think there is a leak in the system since I am not holding boost as I should (Might be as simple as the BOV being too loose), but I don't know if that would cause the AFR to bounce even at idle...

tuj

So (and yes I know this comes up all the time), what is to blame for the fuel milage (or lack thereof)? I understand that the rotary combustion chamber shape is thermally inefficient, but besides that, where are we loosing so much in everyday driving?

It looks to be like the lamda values up to 4k are pretty reasonable off the stock tune on the dyno's I've seen, although I'm sure those were done at WOT which probably throws things off a bit.

I consistently get 13 mpg in city driving (this is over two years of ownership, and 4 different flashes), shifting at 4k, crusing in 4th. I get 20-22 on the hwy crusing at 75.

BTW: I'm talking about the STOCK cars here.

zoom44

shift at 3k cruise in 6th. dont take short trips. short trips mean time spent not warm. when its not warm the car is not in closed loop. lots of short trips mean lots of time spent NOT in closed loop. means it sucks fuel. that trip around the block for lunch will cost you 2 mpg at least a fill up. on the highway cruise at 70 to get 24

tuj

Yeah, heard all those tips before. Cruise around town in 6th? No thanks. Short trips: can't help it that my commute has become short.

Just wanted to confirm that the normal idle AFR's weren't the issue. What kind of AFR's does it run at idle during startup enrichment?

zoom44

at about 42 -43 with cars in front of you you should be in 6th above 35 you should be in 5th. downshift when you need extra oomph- thats why you have gears. as for the short commute- i heard someone say recently their commute since they moved was like 6 minutes if all the lights were green. my question- why are they driving? walk or ride a bike

tuj

We're way OT now, but believe it or not, it does rain, snow, and get hot and cold outside. Walking / biking are not always answers. Public transit? Ha, most of America has yet to really get that concept.

two rotors

My A/F is consistently in the 14.3-14.8 range at idle when warm.It takes a few seconds for the O2 sensor to warm up on a cold start,but my A/F is in this range as soon as the O2 sensor warms up.My LTFT at idle is -18% these days.
The trick for fuel economy is the position of the the throttle pedal.Having the Greddy E-01 with the boost gauge is useful keeping manifold pressure as low as possible and hence consuming small quantities of fuel.
Unfortunately the turbo is really bad for prompting you to make positive pressure in the manifold and hence consuming copious quantities of fuel.

zoom44

raingear, winter coats, l drive when its too bad