lakeffect2

It's about a year now that I am fighting my AFR's going immediately to 10.00 (limit of gauge) and staying there even with the slightest of pressure. Nothing I change seems to give me any headway or clue to resolve it, even after reading countless threads on the subject. As you can well imagine, gas milage sucks, as the ECM is just dumping fuel in all the time.

I'd like to see if this is a AE TPS issue vs AE MAP issue. I'm in $8d, using super_aujp-v4. How do I turn AE MAP COMPLETELY off?

I've already raised PE to kick in at 80% to keep it out of the problem. No positive effect wahtso ever.

gp90gta

iTrader: (1)

Sound more like a VE and minimum air setting problem, AE is more of a fast throttle setting, AE is like a pump sot on a carb, it adds lots of fuel quickly then decays quickly. Fuel on a molecule level is heavier then air so with quick throttle changes the air move much faster then the fuel so they separate, causing a lean condition or even a lean pop in the intake.

Six_Shooter

iTrader: (2)

I agree, if the rich condition doesn't decay rather quickly, I'd be looking more at VE table, possible MAT comp table, even something mechanical, if this is an "all of a sudden" problem.

Years ago, I washed my engine bay at a car wash, and for some reason, one of the coils died while doing it (FWD 3.1, coils are mounted low and on the front of the block, just behind the rad), which is rare because the coils can usually get submerged and not have issues. Anyway, I was way rich after that, until I replaced the failed coil.

FWIW, the only way I know how to disable AE, is to zero out the tables.

lakeffect2

I would agree that it is possible that it is some other problem masking itself. It certainly is possible that the VE table are rich, but what I see is a very slight amount of foot pressure dumping fuel. The fuel table might add 1% more, yet the pulse width can double or triple and hold there. So I think it has another cause other than only VE, as a 1-2% change in the basic fuel table shouldn't cause such a gross change in the pulse.

I am trying to eliminate causes, and want to see if AE is the culprit. So which tables would I choose to zero out? ANYTHING that has an AE MAP component? Or is there a primary element, and leave others unchanged?

RBob

iTrader: (1)

To eliminate dMAP AE, set this table at the maximum:

@ L859A
; DIFF MAP for Accel Enrich Enable

That table defines the amount of delta MAP required for MAP based AE. Should do the trick.

For dTPS AE, it looks like this value will do the trick:

L8530: FCB 12 ; ACCEL ENR LASTS 12 REF PULSES

Set it to zero and dTPS AE should go away.

Making these changes should also make a difference in how the engine runs. If they work as I think they should may even get a lean pop from a throttle stab.

RBob.

Street Lethal

iTrader: (16)

Are you sure it's in the the tune? Have you checked your injectors and regulator's diaphragm?

lakeffect2

That's a fair question to ask. I see reasonable afr's during warm and idle times into mid 14's.

Today I was digging into old bins from last year, as I also noticed that Highway mode, even though on, never seems to activate to see AFR's in the 16's, like UI did last year. I found one from last year noted as "highway on" and loaded it into one of the the prominator memories. I can switch between old and new bins with the turn of the dial.

I immediately saw better AFR's even though those old fuel tables have about 10% more fuel across the board. So I'm doing a comparison to the old bin and new to see what's different and that should help narrow down the culprit.

Changing the delta Map AE to 90% and 100%had no effect what so ever on the AFR 's going to 10.0. So comparison should help. At least I know the old bin was headed in the right direction relative to the new one.

So in answer to your question, if I can see an instant change for the better with the flip of a switch , I think it helps to rule out hardware issues in favor of software concerns.

Six_Shooter

iTrader: (2)

That doesn't rule out hardware issues at all, it just shows that a different bin will change something about how the engine runs.

I think those of us that tune the ECMs sometimes get so focused on it that we forget about mechanical parts and that they wear out and/or fail. We then try to tune around it. I can tell you from experience, you can fix something mechanical by pressing a few buttons on your laptop.

lakeffect2

Thanks for the insight, I appreciate it.

In retrospect, I rather sheepishly admit that recently, one of my favorite "hardware" ECM tuning devices has turned out to be a

BIG FREAKING SLEDGEHAMMER!

Six_Shooter

iTrader: (2)

Haha

JP86SS

iTrader: (1)

You got mail !
I dumped a bunch of my files on ya.
Hope it helps sort it out.
Jp

lakeffect2

GOT IT!

I'll keep things posted after i get a chance to compare files. So far looks like if I went up on a parameter, you went down and vice versa.

lakeffect2

A quick update is that info from JP has helped emmensely in allowing me to make some comparisons on bins. after I've sorted out some details I'll report back on what was different and what seemed to be helpful to reduce my AE AFR's away from 10.0.

A reload of altered parameters was tested this morning with positive results, seeing AFR moving away from 10.0 and not staying there. It's too early yet to say it is totally cured, but at least now I have a workable bin that is headed in the right direction to work with and make comparisons to.

Thanks JP, for all your help and encouragement.

Dave

lakeffect2

ITS ALIVE!!

msm z28

Just curious what it was that helped you, if those files from JP helped and if you could share the info with us here. I have a similiar, but not quite so severe problem of going to very rich AFR's when stabbing the throttle for longer than I would like, even though my VE map seems pretty close to being right on.
Thanks for any tips you can share..
Sal