Got my 91 camaro TBI with 383 stroker, rv cam, flat top pistons, l65 injectors, 18 psi spring, stock intake and exh manifolds for smog 2.5" magnaflow dual cat into 3" single muffler, G2 adaptor on 8746 ecm anlu bin file, modified BPW to 95 after doing the flow calculations and my BLM's are at 150 during cruise and 128 during accel. O2 sensor reads 750-850mv at idle showing rich but normal up down during cruise, a lil lean during heavy accel. what am i missing or doing wrong? im new to diy prom and appreciate ya'lls help with this. i've uploaded a ziped file with my bin & datastreams using tunerpro rt. I've read alot of the beginner stuff but im still at a loss. why my o2 sensor reads rich but blm is seeing a lean condition and commanding ecm to enrich afr?

 

Not sure I fully understand everything you're saying about the symptoms... But in any event...

Don't necessarily conflate the NB O2 sensor reading with the 150 BLM. Assuming the bin file has a max allowed BLM higher than 150 (like maybe 160)... the 150 BLM means that the ECM has added a bunch of fuel to get you back to stoich due to some malfunction that it's seeing (on the side of the engine that has the O2 sensor). The malfunction was causing the engine to want to run lean, so the ECM added fuel to compensate. Whatever the problem is could be globally affecting the entire engine (fuel pressure, ignition coil, sensor, inadequate tune, etc) or it could be local to the O2 sensor side (plug wire, plug, injector, etc).

Actually you can be running 150 BLM and still showing momentarily "rich" (for what it's worth on a NB O2). As long as the ECM has adjustment range on the mixture, it'll still try to maintain stoich, so you'll see the O2 sensor voltage moving around. Again, all the 150 means is that the ECM has compensated for the malfunction by richening the mixture and reporting the 150 BLM as an indication that it's done so.

If the BLM reading gets pegged at the max value allowed in the bin (say 160), then the ECM runs out of adjustment range and in that case you may see the O2 sensor peg lean for long periods of time down around 0-150 mV.

But in your case, I would expect the O2 should be swinging around the center point of ~450 mV and not stuck at any one voltage for any length of time. So it shouldn't be sitting at 750-850mV unless there's something wrong with the sensor.

It just sounds to me like you need some tuning done.

 

Well I take it you didnt bother to open my bin file to see my tune or run my data logs to see for yourself what is happening, but i appreciate your input. yes my BLM is max at 150 & min 108. It actually maybe that i am running lean and ecu is commanding rich cuz since i last posted i took out the plugs to see what they look like and they are orange / high speed glazing. replaced them and adjusted bpw to 100. now the o2 sensor still pegs at around 700-800 but the blw is now near 128. int however went down to 115 and commanding lean. another thing i noticed is that when i end my test drive and shift from drive to park,,, the rpms go way high to 1400 and stay there for a min then slowly come back to normal idle. any chance this is because i have the aldl connected and the prom/ecm is programmed to raise the idle when aldl is communicating? i know ive seen this setting before in a $42 bin but i dont have that parameter in my current $61 bin. any ways.. here is some more datalogs ive taken today. if u or someone else can take the time to look at my tune and tell me were im messed up id appreciate it.

 

The reason I didn't look at it is because I didn't have access to my computer at the time and I would still need to download the right mask to even view it in the first place (I only have $8D, $DA3, and $EE).

I'll see if I can look at it later today or sometime this week.

 

You have a bunch of errors showing up....

24 - VSS
43 - ESC
51 - PROM
53 - VATS

I would try to resolve those first. At that point if you still are showing high BLM's, you'd probably want to start richening up the fuel curves. But I'm not familiar enough with this particular mask to tell you specifically what to change unfortunately.