What parameter adjusts $88 ae length?

[f85gtron]

I'm having an issue with ae. It seems to last too long when entered in to. My blms and int start off fine, close to 128-ish, but then, the int drops off the cliff and blm follows.
I've learned to ask before making changes....

[RobertISaar]

if you're certain the length of the AE pulse is the issue and not that you're in a portion of the VE map that requires adjustment:

AE multiplier vs AE pulses. pulses beyond 8 use the 8 value.

if this is in a situation where the throttle is opened and then held still(and the engine "catches up"), AE is only in effect for a really short amount of time, until the D-TPS thresholds(which are lag filtered) are met to leave AE, that likely isn't long enough to see via the INT.

if the situation is the throttle opening enough to enter AE and keeps opening fast enough and far enough to stay in AE, that is tricky to tune considering it would be hard to say where you'll be at in the AE pulse multiplier table.

[f85gtron]

Thanks for the reply. as I accelerate, then level off, it runs 128-ish for a couple seconds, then into runs south down into the low 100s for another second then recovers.

[1project2many]

A problem such as this, if it's occuring under mild acceleration, is usually a combination of factors. Often what happen is the VE table is slightly lean in the cells representing increased load. AE may already be providing slightly more fuel than should be needed to cover a lean spot. When the throttle is opened the engine begins to run slightly lean and O2 readings begin to drop as engine rpm increases. Int may be responding by increasing although BLM is likely not to change. As the vehicle accelerates the driver begins to let off the throttle, shifting to VE cells that are more correct for the engine load. But the ECM is still responding to the lean condition and adding fuel. At this point INT will be high, BLM is likely to be near correct, and O2 will be showing rich. Often the O2 reading goes so rich the ecm will drive INT toward the lean limit and BLM will quickly follow suit. To make matters worse, DE may not even have been addressed. So the decrease in throttle angle which resulted from the vehicle coming up to speed does not result in the correct decrease in fuel delivered to the engine. You can usually see the sequence if you watch O2, MAP, TPS, RPM, and INT. Be sure to include IDC also, if its availble in your datastream.

There are three modes you have to work on simultaneously to solve this. First is the VE. You have to make sure VE is correct throughout the load range. Second is AE. AE is a very short correction. Third is DE. DE is the opposite of AE and decreases fuel as throttle is closed rapidly. Both AE and DE only exist because the ecm is unable to correct for quick throttle changes in the VE tables alone and they are for rapid corrections. They could be thought of as "helpers" for the VE.

One way to help isolate what's going on is to disable closed loop. Lean will show up as low O2 values and might even cause a noticeable stumble. Rich would drive O2 high and could even create black smoke. In order to monitor the VE in the areas in question, it may be necessary to create a situation where you can operate at the correct rpm and load for a longer period of time. Here in New England we're lucky enough to have plenty of hills to allow this fine tuning to occur and I've actually zeroed out AE in order to work with only VE. BTW, eliminating AE results in a very difficult vehicle to drive. When VE is correct you can usually see AE and DE effects pretty clearly. They both show in the O2 reading right after delta throttle. Once you have AE, DE, and VE correct you can re-enable CL and watch your BLMs stay right around 128 even during mild transitions.

[f85gtron]

Thank you for explaining the interactions between AE and de and effects on int. I've been tuning only a couple months now and am working on AE de and such, now that the VE table is close. Maybe its not as close as it could be.
Could forcing open loop and watching target a/f effect the same results as watching o2 voltages? it's easier for my brain to process ....dont know why. probably because it doesn't move as fast 

Ive uploaded the adx, log, and current working bin (only change since log is the o2 delay to accomadate the distance from the exhaust manifolds. I was experiencing idle hunting )

You can see in the log what I've described happening, but with limited experience, I may be barking up the wrong tree?

[f85gtron]

I believe the problem to be de and the VE table. I'm working harder on b.l.m.s and its improving. next, ill be asking about de ☺

[1project2many]

Learn to use O2 values. You can use the recorded data to view monitors so you can play them back and pause at any position you'd like to review. You can see an example of what's happening at 2:46 in the log by selecting TPS, IPW, and O2 . TPS increases sharply. IPW increases quickly for AE then drops off so O2 spikes rich and drops back toward lean At the same time, INT goes high high to correct for temporary lean, and BLM follows INT. Now if load were to stabilize the BLM would be rich.

I'm seeing this as several shades of blue which is hard to track but if you can get a few different colors you can add MAP and RPM to help identify VE cells that are involved and make the data more viewable.

Work on the fueling so increases in throttle angle and MAP don't drive O2 lean. If you can get this resolved you'll be amazed at how smoothly the engine responds.