[Rednaxs60]

My thread "1985 Honda GW - ECU Replacement - Getting to the Road" has gone the distance. The GW is now ready and had an initial road test/trial. Time to concentrate on tuning for the road. Here's the link for the Getting to the Road: viewtopic.php?t=6083

@PSIG has perused the initial road data log and tune:

"Great! Now, open the log in MLV, Open Tune to the one you used, and review the log. I didn't see any obvious misfires, but you should look closer as you know what was happening, and I don't. I do see that your effective table is from 60kPa and up, except decel, so most of your tuning will be that upper half of the table.

Then, open VEA, and just for giggles, run it with current settings, just to see what it suggests. You can hover over the suggested changes table on the left, and see what the old value was, and if the suggested RED value is appropriate. Click the "X" at the top-right of the popup to not accept, and just review it. Close it, go make your specific settings for VEA, then do it again and if you like it, accept, and save the new tune."

Have some housecleaning to do but these issues are subordinate to getting the engine tune for road riding. More learning to be done and things to do. Cheers

[Rednaxs60]

@PSIG - did a comparison of the VE tables. Not too far off from my reckoning. Intended to decrease the VE cel values in the higher RPM ranges. A couple of more road rides and check the plugs as well. Going to leave as is until the New Year, then start tuning in earnest. Here are the tables:

VE Tables.jpg (76.88 KiB) Viewed 5837 times

Question - baro sensor and how the sensor input signal is interpreted. Have reviewed a lot of forum and internet posts. Have tried my board skills, no joy and a Denso MAP sensor, no joy. I have data for the CFI PB sensor:

5" HG - 4.1V
10" HG - 3.4V
15" HG - 2.67
20 " HG - 1.95
25 " HG - 1.3V

Good linear line. The TS software has input for 0V and 5V. My perusal of the software indicates that at 0V Kpa is a low cell value and at 5V it is a high cell value. I can extend the line to get close to the voltage readings. Here's the graph:

PB Baro Sensor Data.jpg (44.65 KiB) Viewed 5837 times

Using this sensor is the easiest way to install one. Can use the 5V signal that the Hall Effect sensors are using, ground as well. Only have to get signal to the ECU and install a signal resistor. There is a spare 5V ECU pin that can be used as well, but requires additional wiring.

Another road trial this morning. Will compare VE tables after this ride as well.

Thinking the brakes will get done tomorrow.

[Rednaxs60]

Today's trial logs and picture. Before I started I changed the VE cell values down one point from 60 Kpa to 46 Kpa. I changed the RF down one point as well. Looking at the VEA VE table and mine is slowly getting to it. Not too fast though. The VEA Table shows a change in the higher Kpa numbers, engine was operating in the 95 to 80 Kpa range when at higher speeds. Took it up to 100 KPH on the highway. If I was a betting man, like to have breakfast and donate to the government at the casino, I would think that somewhere in this range is where Honda changed to an AN fuelling profile.

Here's a picture of the VE tables from today:

VEA - ECU VE Tables 30 Dec 2023.jpg (101.54 KiB) Viewed 5805 times

Here are the logs:

Archive.zip

(535.03 KiB) Downloaded 69 times

Time to look at the plugs and do maintenance on the brakes.

[PSIG]

As you get comfy with using MLV, you are only adjusting to random AFRs that should run "OK", and getting the whole table reasonably coordinated on that random target. That's fine, and you're learning the tools. When you get back to it after the new year, the new focus will be diagnostic tuning, in order to find the best AFR in each area for optimal operation. A new viewpoint for tuning, not adjusting to an AFR, but testing for the right AFR to adjust-to. See you next year!

[Rednaxs60]

@PSIG - thanks for the comment. The VEA table is not that far off the ECU VE table. Going to adjust some of the ECU VE table cells especially in the higher Kpa ranges and do another ride today.

To all who are following, may you have a safe and prosperous New Year! Cheers

[Rednaxs60]

1 Jan 2024. Time to get tuning in earnest. Have had the bike out and did some logs as you can see from my other posts. Have had it up to 125 KPH, and working not too bad. Running out of MAP at this higher speed/RPM.

Did some RF changes today, three in total. The RF calculator indicates an RF of 10, but the engine likes 5.9 to 6.2 better. I kept the initial RF value when I went sequential, did not do a TS recalculation. It is a trade off. If I use an RF of 10, then I will ave to adjust the VE values. Larger RF value requires a reduction in VE table values (rhetorical)? Using plug colour to assist as well.

[PSIG]

You can mathematically scale the R_f against the VE table values, so the net effect is the same fueling - just different multipliers. I wouldn't offhand, as the higher resolution at lower R_f has benefit.

That said, I would not goof with any settings at this point, as you cannot yet see weaknesses to use other settings for, and cannot as-clearly see benefits or detriments to a specific settings change. Run what settings you have until you have specific data to indicate otherwise. It's running, and not too badly, so I would jump right into tuning tests to find best AFRs and best timings, beginning at warm idle. Then, you'll be able to see more clearly what injector latency or coil dwell is most appropriate, warm and cold start values, R_f and VE resolution, etc.

[Rednaxs60]

@PSIG - thanks for the comment. I do like being able to back the bike out of the garage, get everything ready to go then ride. I did notice that as I changed t a higher RF with the same VE table values, started to hear a cylinder "gurgling/sputter" - ever so slight, changed the RF back down and it went away. Going to call it this as I don't have a different way to describe it.

I have checked the plug colour. The right cylinder bank, cylinders 1/3, is lean (plug colour is white), coils are firing. The left bank, cylinders 2/4, is slightly richer, not a whole lot. Will probably do some VE table cell value adjustments.

I have four data logs to look at now, parameters almost the same, but will be looking for similarities/comparables. Comfy chair and favourite libation is definitely required.

Mentioned that the MAP is getting maxed out, may not be an issue. This indicates that the VE, ignition and AFR tables will be using the 80 to 95 Kpa range for engine operation in SD fuelling mode.

Have been doing more reading into engine vacuum. There is a small volume of air that can be brought into the engine as @PSIG has mentioned in a post on one of my other project threads. We refer to the engine vacuum, but in reality it is a lower pressure than atmospheric pressure. This pressure differential, engine vacuum versus atmospheric pressure, is how the air is drawn/pushed into the air chamber and down into the cylinders. With this understanding, and seeing the MAP reading in the higher readings closer to 100 Kpa (atmospheric pressure), the engine can operate in a rich fuelling condition, more fuel than air. My thoughts and understanding about this issue.

Have also noticed a significant swing in the fuel injector PW from approximately 2.5ish to 4.3ish depending. Will be reviewing the logs and determine if there is a correlation between MAP and fuel injector PW.

The TPS is around 20 to 30 percent open when the MAP reading is in the higher range(s). Indicates to me that a change to an Alpha-N fuelling profile may be beneficial. Honda may have seen this and did its design to compensate. May be the reason for four fuelling maps, two for SD and two for Alpha-N, in the original CFI ECU.

This is going to be a very interesting phase.

[LPG2CV]

Hi Earnest So glad you got to ride it.

Alpha-N is a further level of complexity, that you don't need just yet, until you fully understand fueling.

RF, is a ball park value. It's used as a base reference for fueling. VE, is simply a % multiplier of the RF. In the VE table, you set various VE values based on the fuel needed under those engine conditions. Those conditions currently being MAP and RPM. So where as VE is a specific value for one cell in the VE table, and changing it, only affects that one cell, changing the RF, will affect the whole of the VE table. Think of it as a global change.

PW, is the pulse width of an injector. Badly named I think, as it is actually a pulse length. However it is what it is, and that is, the duration the injector is held open to deliver fuel. It is connected to VE (and enrichment), rather than MAP. It just follows that VE values tend to get higher as MAP rises. So PW is just a calculation for the current VE + any enrichments.

Hope that helps

[Rednaxs60]

@LPG2CV - thanks for the comment. Be a bit before I get into Alpha-N or the blended aspect, but I have time - need to research and understand better. Just going to ride for a bit, a few minor tweaks along the way. Have started to do EXCELL spreadsheets regarding tuning values. Put one together for the VE values from yesterday.

Engine speed up to approximately 4000 RPM, only half way to red line. I did a comparison of two road data logs. The white columns are the first road trial of the day, the yellow columns are the second road trial. Where there is a difference between VEA analysis and the ECU VE table values, you will see a "xx/xx" value. For example, road trial 1, white columns, Kpa of 90 at 1000 RPM, the VE value is "69/66". The "69" is the ECU VE Table cell value, the "66" is the VEA value.

VE Table Data - 1 Jan 24.jpg (83.23 KiB) Viewed 5453 times

I notice that the VEA analysis values are generally lower than the ECU VE table values being used. I would think this would affect the fuel injector PW.

I notice that MAP and PW are trending together, MAP goes up, PW goes up. AFR does the opposite, MAP/PW goes up, AFR trends down, conversely - MAP/PW goes down, AFR goes up. Don't notice any other inconsistencies, wouldn't know what a misfire looks like for instance.

Need more data to look at and compare. Keeping below 4000 RPM, approximately 125 KPH (80 MPH) and use the same route for data logging. A couple of longer rides into town for comparison as well.

Cheers