I have the BLM's so fine tuned I'm down to tuning via the integrator.

When I hit the gas, I initially see the INT drop down to ~110-ish. After a few seconds of constant throttle acceleration, the INT will increase up to 125 and bounce around between 125 and 132-ish.

Question: Is that initial drop due to the AE coming in (intuitively I'd think it is)? Put another way, does the computer recognize that it's delivering fuel in excess of what's in the VE table and that it should (or shouldn't ignore) that excess showing up in the O2 sensor read out, and therefore the INT readout?

 

Probably have a smidge too much fuel being added via AE. GM usually sets up the tunes so that the INT increases during an opening throttle event. This prevents a sag as the AE runs out.

As for your question, some masks have an option flag to reset the INT during AE. In this case the INT holds at 128 until the AE event is over.

The worse use of the INT for AE is in the $88 mask, AZTY calibration. With so little AE being added the INT will sky-rocket to cover for the lack of fuel. Then when PE is entered, such as when rolling into the throttle, the INT gets locked at the current value.

Since the sky-high INT is also dragging the BLM up along with it, can you say 'sloggy rich?'

So back to where your tune has the INT dropping, as long as it doesn't drag the BLM down with it, and/or create a slight sag as the AE runs out. It isn't much of an issue.

RBob.

 

Thanks. Yeah, this is $8D.

The update rate of the BLM is probably too slow for it to react to this. We're talking on the order of about 5-10 seconds... I guess I can keep playing around with it and see what I get.

 

Taking a quick look at $8D, if the comments are correct can lock the INT at 128 during AE via option word 3:

L8018, b1: INT RESET WHEN Accel Enr IN WORK

IIRC, I've tried this and found it better to allow the INT to adjust. This covers for lack of, or an excess of AE. Although only to a point as the above mentioned side affect can occur.

Can always try it an see how it works out.

RBob.

 

Ah-hah. That explains why my INT always goes to 128 under a touch of throttle. I just checked my ABTB based BIN for 32B and LC016 bit-1 is enabled. That'll be going into the XDF.

So is it correct when INT goes to 128 under AE you lose whatever correction the INT was giving you and your pump shot could end up making you richer or leaner than you want depending on where INT previously was?

It appears ARAP (6E) and BUA (32) also have this enabled by default.

 

Yes, the short term correction is lost. It resets the INT to 128 and prevents the BLM from moving until the AE event is over.

RBob.