7747-7427 Swap

[Scooterwrench]

Went out and logged some data. I'm rich in most of the cruise regions,dead nuts at WFO so I think my BPW is right but if I'm correct I need to fatten it up a little up there.

 

[PlayingWithTBI]

I'm rich in most of the cruise regions,dead nuts at WFO so I think my BPW is right but if I'm correct I need to fatten it up a little up there.

Is your VE table(s) 85% at, or below at high MAP and RPMs? If so, just leave your BPW alone and fine tune the middle of your table(s).

As an example here's one where I'm going up into ~90% at 100 MAP and 6000 RPM. I could adjust my BPW to get it down to ~85% but, I'm not worried about that until I get my AFR under control.

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Then smooth and interpolate to get something like this (from the same table).

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[L31MaxExpress]

As long as you are under 100% VE no need to change your BPW settings. Duty cycle under 85% is what I like to see on TBI atleast. If you go over 85% DC with TBI you need to raise the fuel pressure or go to larger injectors. I noticed you were at 100% duty cycle but also very rich, so when you lean it out duty cycle will drop.

 

[PlayingWithTBI]

I noticed you were at 100% duty cycle but also very rich, so when you lean it out duty cycle will drop.

Yeah, that's my plan anyway thanks!

 

[Scooterwrench]

Yeah, that's my plan anyway thanks!

Have you ever discovered this;

Adjusting VE Fueling tables with BLM data Tutorial!

There's a lot of questions about how to adjust the fueling VE tables with BLM data so I'm attempting a tutorial to understand the theory. Lots of it takes some practice and understanding of what is happening and how to make adjustments. We have great tools for this starting with TunerPro RT...

www.gearhead-efi.com

 

[PlayingWithTBI]

I checked that out a few years ago but it was TLDR all of it. A lot of the smoothing tables are now easier with the Interpolating function. You don't have to go row by row and column by column but, like I said, this is pretty new to me too.

After our earlier discussion, I spent about 5 minutes adjusting my tables to get the AFR (to ~85) and DC lowered. I'll try it out sometime but, here's an example. Note: the EBL has 3 tables including an extended one to 8000 RPM.

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Here's the "high speed" (your "Off Idle") 3-D graph you can compare with the one above. Now, I'll run some Learn VE logs to fine tune them.

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[Scooterwrench]

I checked that out a few years ago but it was TLDR all of it. A lot of the smoothing tables are now easier with the Interpolating function. You don't have to go row by row and column by column but, like I said, this is pretty new to me too.

After our earlier discussion, I spent about 5 minutes adjusting my tables to get the AFR (to ~85) and DC lowered. I'll try it out sometime but, here's an example. Note: the EBL has 3 tables including an extended one to 8000 RPM.

You must be registered for see images attach

Here's the "high speed" (your "Off Idle") 3-D graph you can compare with the one above. Now, I'll run some Learn VE logs to fine tune them.

You must be registered for see images attach

I opened the off idle table and instead of going by rows and columns I highlighted the whole table and smoothed then opened the 3D graph and pulled up the dip in the 4000-4400 range. I think I have a good table to datalog with tomorrow morning.
I found this spreadsheet for calculating BLM's,it has tables for WB too.

GearHead EFI Forums

Fuel Injection Conversion and tuning information and diagnostics GM ECM!

www.gearhead-efi.com

I messed with it a little but not enough to get any decent results,probably my dumb @ss.
If I can't figure it out I'll do it the old fashioned way BLM/128 X current VE cell.

 

[Scooterwrench]

Well not much progress today,damn cuckoo clock. I did try running a 7427 truck .bin figuring the fuel table would be closer to the engine in my truck. Went around the block and what a pig. When I got back I looked at the spark table -2 at 400 RPM and 100 MAP, -1 at 800 RPM with a high of 31 at 6000 at 50 MAP. Bet the truck that .bin came out of was a gutless wonder.

 

[Scooterwrench]

Well I'm getting closer. I datalogged another trip and it was still rich then it hit me,I hadn't added enough timing and was probably getting false fuel data from the timing being so far retarded that the O2 sensor was reading fuel that was still burning in the exhaust man. I used an old trick with new tools to find out what the engine wanted for idle advance by unplugging the IAC and timing bypass connector then firing it up and rotating the dist. by hand until I got the lowest MAP reading. Timing light said 18deg. Set the timing back to zero, shut it off and plugged it all back in and cleared the codes(new T-Pro does that now). I dialed in anything below 16deg in both spark tables to 16 with the exception of the 400 RPM range from 70 to 100 MAP in the idle spark table, I set those to 0 to make life easy on the starter. Popped in my datalog tune and went around the block. The thing will actually get out of its own way now. The DL tune has no PE or DFCO. I had to work on paying jobs so that's as far as I got today and I really don't want to add any more timing until I get the right KS for this ECM.
The new T-pro is supposed Interpolate but I don't know what that does or how to do it.

 

[PlayingWithTBI]

I dialed in anything below 16deg in both spark tables to 16 with the exception of the 400 RPM range from 70 to 100 MAP in the idle spark table, I set those to 0 to make life easy on the starter.

I don't think you need to do that, FWIU the ECM doesn't use the SA tables until it gets feedback of 400+ RPM but, I may be wrong. It starts a zero SA unless you change the "SA-Initial SA" (in SCALARS) and set your Initial Timing with the EST Bypass wire disconnected. This way, you wont be throwing of your entire SA Tables by having the distributor at something other than zero. As an example, mine actually likes 10° on Initial Timing.

The thing will actually get out of its own way now.

Good to hear

The DL tune has no PE or DFCO.

I don't care for DFCO - it acts too much like a "Jake Brake". Unless you plan on pulling a trailer in the hills

The new T-pro is supposed Interpolate but I don't know what that does or how to do it.

Try it, you'll like it Take a table and play with it. Change a row or column, highlight the whole table or part of it, and "Interpolate X, Y, or XY" If it comes out weird, don't save the table and try again - fun stuff!

Yep, you're on your way to catching the disease.