4.3L to ?? swap.

[L31MaxExpress]

There are a few other PE-relevant parameters found under other (sub)menus. @df2x4, can you ferret them out and post a screengrab? They might precipitate some additional comments.

I for one tweak the "PE enable" to trigger on vacuum (actually the MAP equivalent), around 6-8". I'm sure I'm not alone. That table's in there, somewhere, along with some others.

Yea about 70 kpa works well provided the truck is not at high altitude. In that scenario the TPS entry would be maybe 30-40% or a little above where the truck normally cruises. My van on flat road cruises at about 15% TPS at 70 mph.

I do mine a little differently. I like my PE to come in as an extension to the throttle once the manifold pressure is near atmospheric.

 

[df2x4]

I for one tweak the "PE enable" to trigger on vacuum (actually the MAP equivalent), around 6-8". That table's in there, somewhere, along with some others.

I'm not seeing that one. In Tables>Fuel I see Power Enrich Fuel Equiv. Ratio Vs. RPM, Hot Power Enrich Enable % TPS Vs RPM, Cold Power Enrich Enable % TPS Vs RPM, Power Enrich Fuel Correction Vs. Coolant Temp, and Power Enrich Fuel Correction Vs IAT. Pictured here in that order, from left to right.

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[1998_K1500_Sub]

I'm not seeing that one. In Tables>Fuel I see Power Enrich Fuel Equiv. Ratio Vs. RPM, Hot Power Enrich Enable % TPS Vs RPM, Cold Power Enrich Enable % TPS Vs RPM, Power Enrich Fuel Correction Vs. Coolant Temp, and Power Enrich Fuel Correction Vs IAT. Pictured here in that order, from left to right.

Ah... either you haven't found the table (sorry I can't just show it myself, but I'm 1400mi from my JET DST laptop)... OR, perhaps more likely, that table's specific to my 1998 L31 5.7L black box ECU and doesn't show up (in the same format anyway) in the newer LQ4 6.0L from which you're pulling these screengrabs.

 

[Supercharged111]

I do mine a little differently. I like my PE to come in as an extension to the throttle once the manifold pressure is near atmospheric.

I like my downshifts the same way.

 

[df2x4]

either you haven't found the table

Entirely possible, perhaps likely. I've loaded this software maybe 20 times since I bought it, and I think most of those were to pull screengrabs of things I have no knowledge about.

 

[1998_K1500_Sub]

Yea about 70 kpa works well provided the truck is not at high altitude. In that scenario the TPS entry would be maybe 30-40% or a little above where the truck normally cruises. My van on flat road cruises at about 15% TPS at 70 mph.

I do mine a little differently. I like my PE to come in as an extension to the throttle once the manifold pressure is near atmospheric.

I like my downshifts the same way.

There are valid reasons for different approaches to enabling PE (or enabling the shifts up / down, TCC lock / unlock, etc.) and readers should take note of the variations.

If I was often pulling a trailer or driving at high elevation (as @L31MaxExpress noted) my method might enable PE quite often and kill the mileage. A variety of other, differing scenarios exist which justify different and very appropriate approaches.

Sometimes I'll configure the ECU with a different "tune" for the situation, e.g., a long trip from Illinois to Cooke City, Montana with a loaded trailer vs. a lightly-loaded 250mi trip north to Tomahawk, WI.

 

[shovelbill]

@shovelbill I think I found the cylinder volume setting that @1998_K1500_Sub mentioned earlier. It's under Constants>Fuel Parameters. This is from my dad's '06 3500 stock tune, so what you see for a GMT400 may differ slightly.

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Whoa...thanks.
I think I'll just go back to my corner and leave this be until I'm ready to embark on this tuning endeavor.

I'm capable of learning it, I learned how to tune fuelie Harleys after I got my space invader bike.

I've been following along at home and working on not bugging anyone just yet, regarding this topic anyway, lol.p

 

[Supercharged111]

There are valid reasons for different approaches to enabling PE (or enabling the shifts up / down, TCC lock / unlock, etc.) and readers should take note of the variations.

If I was often pulling a trailer or driving at high elevation (as @L31MaxExpress noted) my method might enable PE quite often and kill the mileage. A variety of other, differing scenarios exist which justify different and very appropriate approaches.

Sometimes I'll configure the ECU with a different "tune" for the situation, e.g., a long trip from Illinois to Cooke City, Montana with a loaded trailer vs. a lightly-loaded 250mi trip north to Tomahawk, WI.

Mine will hit PE in OD around 70 +/- a little just before a downshift. There isn't much wiggle room and I did it that way on purpose. I can choose to try and ride out OD or give the throttle a miniscule poke, let it downshift, and go from there. I've ridden in PE in 4th for a while before, really makes me wonder which is better. I did it more for short duration rises than prolonged use, at least that was the intent. I suppose monitoring MAF flow rate would help me make a decision, but would need the laptop open under those exact circumstances. Mind you this pretty much only applies with a trailer hooked up.

 

[L31MaxExpress]

Mine will hit PE in OD around 70 +/- a little just before a downshift. There isn't much wiggle room and I did it that way on purpose. I can choose to try and ride out OD or give the throttle a miniscule poke, let it downshift, and go from there. I've ridden in PE in 4th for a while before, really makes me wonder which is better. I did it more for short duration rises than prolonged use, at least that was the intent. I suppose monitoring MAF flow rate would help me make a decision, but would need the laptop open under those exact circumstances. Mind you this pretty much only applies with a trailer hooked up.

How about BOTH, lol. In Normal mode shifting my PE happens before a downshift. In Tow/Haul my downshift happens before PE. There are some grades here the van even unloaded uses PE locked up in overdrive to climb the hill. With the 350 it had to drop to 3rd. I am in 3rd when towing currently. Really need to bite the bullet and find a low mileage 6L90E. Having the 4th and 5th gear ratios of the 6L would be nice with my 3.73s for towing. Basically 4th would split the difference between my current 2nd gear and 3rd gear. 5th would split the distance between my current 3rd and 4th. Then it has that nice .667 OD in 6th that will knock about 300 rpm off when I am cruising 70+ unloaded. I feel like 5th would be enough gear I would never drop to 4th unloaded either like I sometimes have to drop to 3rd with the 85E. That deep first would also make getting rolling from a stop really nice especially uphill. 2nd gear in a 6L is nearly as low as 1st in the 85E. I feel the 6L90E would really help keep the 383 where it is happy. The factory vans with the 6L come with 3.42s and even a 3.73 is a noticeable upgrade from 3.42s. My engine idles low and smooth enough and makes enough torque that I would probably keep the stock converter.

 

[1998_K1500_Sub]

Mine will hit PE in OD around 70 +/- a little just before a downshift. There isn't much wiggle room and I did it that way on purpose. I can choose to try and ride out OD or give the throttle a miniscule poke, let it downshift, and go from there. I've ridden in PE in 4th for a while before, really makes me wonder which is better. I did it more for short duration rises than prolonged use, at least that was the intent. I suppose monitoring MAF flow rate would help me make a decision, but would need the laptop open under those exact circumstances. Mind you this pretty much only applies with a trailer hooked up.

Yup, I like that plan. I do something similar. @Supercharged111 as well. We're all thinking along the same lines, but perhaps with minor differences in our objectives.

When I'm not pulling a trailer, I opt for a tune that downshifts more readily and goes into PE more readily, because those events occur during passing, acceleration lanes, etc. which are brief and where I like the quick response.

I also have an aversion to downshifts that'll immediately rev my stock L31 engine to >3000RPM (it dies-off above 3500 anyway), so I require LOTs of TPS input to initiate them.

When pulling a trailer I'll tune differently to reduce shifts (hunting) and reduce extensive PE; I'll simply tolerate the performance. Of course, at very heavy throttle, downshifts and, when appropriate, PE are warranted. I don't want to be running in PE for minutes at a time