RX8Soldier

iTrader: (24)

Ok, I had a serious brain lapse. You're right that it's the FRONT o2 sensor that gives the readings. I know that, but I think I've just been reading too much elsewhere and not paying much attention and mixing up my points.
I will add a "however" lol, I have read that the rear o2 sensor COULD affect readings if BOTH front and rear are showing signs of failure. This was a while ago, so I'll have to hunt the info down.

Anyways, I believe that deep down inside that I was trying to say your FRONT o2 sensor could be giving bad readings.

I'm still recovering from too much booze last week...

rotarywanker

Haha no worries. I'm going to try and do a vacuum test and see if i have a leak. I'm thinking i must. I think fuel pressure must be OK given my strong performance and stable AFR's at WOT. Ugh who knows though. May as well test everything.

RX8Soldier

iTrader: (24)

Yeah man, this is unfortunately what's required when dealing with troubleshooting. Not everything is cut n dry as we'd all like it to be.

Just wait until you delve into the modding world. THAT can and will drive someone with OCD nuts!

rotarywanker

I have no doubt about it! I'm not going to modify a single (powertrain related) thing until the car is in perfect working order. Mods will just add confusion to existing issues. I'm also waiting until my car is past its 100k mile/8 year engine warranty as I may need to exercise that.

RotaryMachineRx

iTrader: (1)

When I had my car tuned I got the idle bumped up to about 800-900rpm.... the dips happen way less frequent for me now. I only noticed it in like 50deg weather and less..... but its sporadic and happens to me every once in a while. Say every 10th time I start it cold and let it idle to fully warm. If I drive the car, get the revs up there then stop and let it idle the popping doesnt exist, it's only when warming up from cold. I have a known very small exhaust leak on my downpipe though too, where the air pump ties into it. I will be blocking that off in the spring, the car is in storage now for the winter.

rotarywanker

Just did a vacuum test at idle, fully warm. Its pulling just over 16. Here is a video.

Thoughts?

http://youtu.be/-8DUdX-Jh1s

9krpmrx8

iTrader: (46)

What elevation are you at? The FSM says MT- 19.6 to 16.6 in Hg.

rotarywanker

130ft

9krpmrx8

iTrader: (46)

Well just over 16 is technically below spec but not drastically.

rotarywanker

I know i have a vacuum leak somewhere i just cant find the damn thing. I built a smoke tester and ran it through the UIM via the VFAD port, sealing the system off at the front of the intake accordion using a nitrile glove. Did this with the engine off. No leak. Are there other places i should inject the smoke? Should i do it with the car running?

Im certain of the leak just because i get a slight whistle, almost like a mini turbo spool, at very light throttle in third gear at 3100-3300 rpm. I capped the vfad nipple to rule it out.

I also have a hand vacuum pump if there is a specific line you think i should test.

But this would explain the low maf flow reading and high fuel trims at least.

RotaryMachineRx

iTrader: (1)

The slight whistle could just be TB whistle