Cdeez

What AE parameters are you guys focusing on when dialing in your AE for a TBI setup. I have been datalogging and dialing in the flow rate and roughing in the VE tables after putting in a 30 PSI marine TBI regulator spring. It's working well so far. 7427 $0E with a WBO2 running open loop.

Now that I've got some of that out of the way I've been moving on to quick throttle stabs to work my way up to WOT tuning. When I do this it pops through the TB and seems to go lean on the WB... I think I need way more AE since I have the single plane intake and the Holley TB on there....

I see 22 different tables concerning AE.... Which ones are the ones to focus on to get this thing some more AE so it won't lean pop when I open the throttle quickly??

Orr89RocZ

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Cdeez

Okay thanks. How about taking the "Delta Map AE" and "Delta TPS AE" tables and multiplying the values by 1.2 and repeating until the throttle can be quickly opened without a stumble/backfire/cough/hesitation? Are these the tables you are referring to and does that change sound like it would get me there? Although, you said, greatly increasing, so maybe I should try doubling them by multiplying by 2.0 and see what that gives me.

Cdeez

I'm getting this backfire when cruising about 40%tps whenever the 4L80 shifts into 3rd gear. This is with the stock AE settings. Hit these two tables with a multiply by 1.3 then by 1.5 makes no difference.

Any ideas?

Orr89RocZ

iTrader: (20)

Cdeez

Ok. I'll revisit the ve tables I think you're right about that. Now, randomly the map sensor is staying locked at 54.6 KPA on the scanner, so I cant resume dialing in the ve tables...... what the f? No error codes.

Cdeez

I dropped the injector flow rate number down a few points and started back over with the stock VE tables and it definitely SOUNDS better at idle and part throttle, even though it is a bit rich that way..... You must be right about the VE table needing some help up top!

I still cannot figure out why my MAP sensor is not showing ANYTHING in the datastream. It's locked at that KPA...... Oh the joys of TBI

Orr89, THANKYOU for weighing in so far!

Fast355

iTrader: (2)

I had a setup that would bog and hesitate when the transmission shifted at part throttle only. It was a large MAP spike causing the same effect in the intake manifold as opening the throttle. The fuel would drop out of suspension and the engine would momentarily starve. My fix was more MAP AE.

Cdeez

Thanks Orr89 and Fast......

It will rev cleanly when you open the throttle quickly with the engine idling and in park. When you're going down the road with the transmission in gear and you snap the throttle open it bogs....

If it needs more AE will it only bog in gear when you snap the throttle open? OR, will it ALSO do it when there is no load on the engine and you just snap the throttle open when idling?

I have to figure out what the hell is going on with my MAP sensor readings before I can revisit tuning the AE, if needed.

Cdeez

Well this is embarassing but it looks like the OEM GM fuel gauge is WAY off..... Filled it up last night and discovered this. Also, since filling it up it is NOT giving me fits when it shifts into 3rd like it was.

My theory is that since I set up the valve body to shift VERY FIRMLY in this 4L80 when I built it, it grabs gears HARD enough that with the fuel level lower than I though based upon what the gauge was reporting, the fuel was rushing away from the pickup in the tank and causing it to go lean.... My turbo LS T56 truck does the same thing, if I ever let it get below half a tank and romp on it, it will do the EXACT same thing....

Cdeez

Still working on dialing in the AE. I have got it to not pop as often/bad when snapping the throttle open but when I smash the throttle to the floor it still does pop and go lean. Should I just keep upping it by 20% on the Delta TPS AE and Delta MAP AE tables until this lean pop goes away?

Also, found a thread I was reading where RBob was talking about reducing the AE filter so it lasts longer.... This was for a 747 that he was speaking of I think, whereas this is a 7427 $0E I'm tuning.
What is the filter called in this mask? I can't seem to locate it but I'm sure it's right in front of me.

Post #20
https://www.thirdgen.org/forums/tbi/...eration-3.html

Orr89RocZ

iTrader: (20)

Cdeez

Looking at a log I did just now, it looks like the RPM flashes to about 2200-2300 and 92 MAP. 90 MAP and 2000 RPM on the wideband histogram has a value of 14.8 AFR.... You think this is too lean for that area?

Also, low RPM and high MAP is showing a AFR of 10.5 in the 800 RPM and 90 MAP area.... Think this is why it's kind of rich and boggy when tipping in the throttle from a stop, especially while moving slow?

I've logged up to 3600 RPM so far. Most of the cells in the wideband histogram are rich in the high MAP area.

If I tip into the throttle enough while just cruising to climb a hill it is still lean popping.

What is weird is that with enough AE to make the lean pop not quite as bad, it also makes it where the engine doesn't rev cleanly in neutral standing still.... Maybe because the fuel table still needs work?

Orr89RocZ

iTrader: (20)

RBob

iTrader: (1)

RBob.

Cdeez

Thanks Orr and RBob.

RBob,

When you were talking about reducing the MAP and TPS AE filter tables, are you reducing the filter tables by 10% AND increasing the MAP and AE tables by 20% at the same time??

RBob

iTrader: (1)

In that thread that was my suggestion.

RBob.

Cdeez

I have rethought my AE procedure. I opened a compare bin and copied every AE parameter I could find from a BMHK 454 bin... I figure this would be a closer starting point since my setup is running nearly 30 PSI fuel pressure, has a large Holley TB (I measured it and it's a tad larger than a BBC TB) and, I have a single plane intake. My reasoning is with all the extra plenum volume plus the added fuel pressure, the AE parameters from that 454 BIN should be a closer starting point for my setup with the parts listed above? Since, that bin, BMHK 454 had ~30 PSI fuel pressure, and the larger TB... That's my reasoning anyways.

I have returned to the stock VE table and just smoothed it over a bit and dropped the 9 or so cells down where it idles to lean it out a bit at idle. Thinking I need to get AE figured out before I try to tune the VE table??

I have been increasing the MAP and TPS delta AE tables 20% at a time, and reducing the two filter tables RBob listed above by 10% at a time... I have done this maybe 4 times now... Doing this has resulted in a rich bog when stepping on the gas from a stop. The WB02 pegs full rich at 10 AFR and the engine bogs for a second then starts to clean up and pull away as the WB02 changes to 12 AFR give or take.. Also, despite the changes to AE, I still have a lean pop when I smash the pedal to the floor.....

I'm wondering if I have now added TOO MUCH TPS AE thus the rich bog for a second when first pressing the gas pedal. And, I'm wondering if what I need for the lean pop I still have is just MUCH MUCH more MAP based AE?????

Does any of this sound right to you guys?

Orr89RocZ

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Street Lethal

iTrader: (16)

Your instincts were kicking in during this post. IMO, and as already mentioned, me thinks you need to revisit your VE map. Especially if you're saying you keep increasing the AE and it doesn't change the outcome above. The kPa will hover in a completely different area when you're in gear, not just due to the targeted RPM, but because of the load behind the engine. It needs more fuel. Monitor where your kPa is hovering in gear, and add fuel to the VE in that area until the bogging goes away. It's not a rich bog, as richness in fuel will slow you down, not necessarily bog like when your lean and you feel the car jerk down, then catch itself again.... .

- Rob

Orr89RocZ

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Street Lethal

iTrader: (16)

Not sure, but I think what he is doing is he's not seeing the momentary lean spike, then just logging the data where it's already caught up after the bog and it is showing way too rich from all that increased AE he keeps adding. Good ole TBI fuel puddling....

- Rob

Orr89RocZ

iTrader: (20)

Cdeez

Well, I have got the AE fairly dialed in after monkeying around with the Delta tables... Now, most of the time, when you smash the throttle open it will drop the AFR down to low 11s or so and take off pretty good. Occasionally it will still lean pop, as seen on the WB02 and the datalogs.

Yes, you guys are right, the VE needs some work. Was thinking I needed to get the AE in the ballpark before I worried with the VE so much, but who knows? More than one way to skin that cat I suppose.

What I have noticed: If I pull the selector into 3rd and then smash on it, it almost never lean pops now. However, if I leave the selector in 4th, it will usually lean pop when you smash the throttle down.

Should be better for the 4L80 to beat on it with the selector in 3rd anyways. Then, let off the gas for a second and shift into 4th.

RBob

iTrader: (1)

Torque management may be pulling too much SA, which will contribute to a lean pop out the intake.

RBob.

Cdeez

I Zeroed the "Maximum Spark Retard for Torque Managment" @ 414B and 414A..... I don't see any other parameters for torque managment. There aren't any hiding are there? Was seeing about 3 degrees less in logs than what the main table is commanding. Which must have been the TQ MGMT.

Orr, if you would post the AE settings you spoke of, I'd appreciate it.

I have been increasing the Delta TPS and MAP AE tables by 10, 20 or 30%. No matter what I do, it still lean pops. Increasing the AE seems to help. But, by the time it's enough AE to reduce some of the lean popping, then this seems to cause it to be very rich on throttle tip in....

The VE map does need work, but every cell logged with the wideband shows an AFR of 12.5 or less. Nothing leaner than that. So if anything the VE table should be on the rich side and not causing this lean pop when you smack the throttle open?

I have thought that maybe I should return to stock AE settings and go do some logs, trying to make note of what TPS or MAP the lean pop is occuring. Just progressively smacking the throttle down more and more until it lean pops. Then from that point in TPS or MAP onwards is where the most AE needs to be added???? Raising the whole talbes is causing it to be rich on tip in.

What to do at this point?

I also wondered about lowering the flow rate a tad, making it more rich everywhere? Then just reshape the VE as necessary once that point arrives.