closed loop Lterm BLM's 120 help

[FSJ Guy]

120's are rich. Not too rich, really, but rich.

Remember, that doesn't mean that your ENGINE is running rich. It just means that the fuel table you have programmed is too rich and the ECM is pulling fuel in order to make the engine run at the correct mixture.

Hope that helps until someone can look at your logs.

[EagleMark]

128 is perfect but in real world you can not obtain this perfectly every day. Even if you get 128 everywhere today when weather chenges so will it. So it's a number to shot for and be close to.

Higher then 128 is lean adding fuel
Lower then 128 is rich taking away fuel.

Most all of your log the car is not warmed up so will be adding fuel/choke. Begining of your log is still open loop so BLM is not in effect. When you get to end of log in closed loop, coolant temp still rising you are running pretty good.

Logs should be started after car is completly warmed up and even driven a little. Want a perfect log for starter VE table then do that then, turn off car, discconect batterey or pull PCM fuse for a miute to clear BLM learn, start car, wait for closed loop and then log! First five minutes will be what you base your VE table at. Ooops! Gave away a secret...

[halfazn]

Thanks, that makes sense. I will try the reset BLM learn tip out. How do i make the car more responsive off the line. If I give more than 25 percent travel from a stop it bogs small audible pops then finnaly takes off?

[EagleMark]

This is probably from the cam change. Normally this is an adjustment to AE, Aceleration Enrichment, like a accelerater pump on a carb. But with the LT1 being a MAF system it would be in the MAF Sensor Calibration measuring air entering the motor after your VE tables are in order. I have tuned an LT1 with cam simalar to yours in SD mode and MAF calibrations untouched with no issues, I'm glad to becuase I do not know correct procedure for tuning MAF calibrations?

Sure you got good seals from airbox through MAF to intake?

I don't know of anything here on tuning MAF? What I was going to do was look at Thirdgen.org for tuning the $6E which is MAF only, no MAP sensor, no SD Speed Density to learn more on MAF tuning.

[RobertISaar]

MAF still uses AE, it's slightly different in how it operates though. obviously no D-MAP component. the later stuff that mixed both S-D and MAF... no idea, i've never played with them.

[EagleMark]

I can't find a parameter for it in the XDF and have not had time or need to see if it's available in hack? Can't find any AE in TunerCat either? With that have been told it was dependent on MAF Calibration. Airflow change = Fuel change...

[RobertISaar]

in $EE? that is possibly one of the least completed XDF/TDFs out there in terms of stuff that's actually in the calibration compared to what is defined.

5B is a good example of MAF in that era. only used in 94-95 3800 cars/vans, some supercharged, most not, but they all use high frequency MAFs and no MAP sensors. it's XDF has accell enrich stuff defined.

[halfazn]

I have tuned an LT1 with cam simalar to yours in SD mode and MAF calibrations untouched with no issues, I'm glad to becuase I do not know correct procedure for tuning MAF calibrations?

You have just got my attention with this. I would prefer a speed density tune in open loop/closed. If you have had successful tunes on LT1 with similar cam, I would like to see how this effects my setup. I am curious if you can assist me in this area while using my .bin file. I would rather be richer than the fixed 14.7:1 ratio used in closed loop so that I can maximize my potential with my current set up. I am not afraid of MPG it means almost nothing to me, I only want performance for a DD and for track. I would like to keep my tune thus far to pass inspections, and venture into the speed density route for my DD.

V/R

[EagleMark]

Well doing the SD tune will only work closed loop or you will not get any BLM learn numbers to adjust your VE table from. From there you could lean fuel table by % to achieve a lower AFR, but this will change with weather. Correct way to tune open loop would be wide band O2 sensor. Still changes with weather... but like I said once the SD tune was spot on and I enabled MAF it was better!

That said, with this ECM this can all be acheived closed loop and still have 12.8 to 1 AFR at WOT with no drivability issues and good MPG if you keep your foot out of it.

Passing inspection is another whole topic depending on what your state does?

[halfazn]

OK, sorry I have been editing my post I mean to correct my tables in SD from the closed loop. If you could look at my BIN and help from here in the SD route. I am open to suggestions.

V/R

[RobertISaar]

but like I said once the SD tune was spot on and I enabled MAF it was better!

and it should, except for the cases where the MAF is actually reading airflow more than once(high amounts of reversion), a problem speed-density and alpha-n don't have. that being said, i like the idea of blended airflow calculations, much more........ consistency, i want to say?