1985 GL1200 Limited ECU Replacement/Upgrade - Part 2

[Rednaxs60]

Have to rely on the engine tuning software for idle timing. Not the best scenario, but have to accept for now. Going to use the vacuum gauges to try and dial the engine idle in as best I can. This picture illustrates what I want to do:

Want to get into the "normal" range if possible. The red circle is where the engine vacuum has historically been with the CFI system. No ability to change this.

The yellow circle is where the engine vacuum is at this time. An increase of approximately 20 to 25 percent, much better. Going to replace the injector holder o-rings, bit fatter - not much, and see what this does. Would like to get into the late ignition timing area with main trigger angle changes and vacuum leak rectification.

 

[Rednaxs60]

Slow progress, but getting there. Timing, always a topic of consideration. Have marked the crank trigger wheel to use as I would on a car. Better resolution for timing the engine. The trigger wheel teeth are 10 degrees each so it's easier to determine the relationship between the tuning software spark table values and where the engine is at. This picture is with the engine running at approximately 1050 RPM. #1 TDC is the valley between the white marks. The case reference point is the screw hole that is being pointed too. The advance is approximately 15ish degrees. Changed the trigger angle and spark table values and the timing moved, as it should and the degrees sort of match. Not a very exact setup right now, but pretty good. Will fashion a pointer and degree plate using the spare engine:

Remove and inspect spark plugs after each trial run. Plugs 1 and 3 are pretty good, not too lean - bordering on a very light tan colour, plugs 2 and 4 are chocolate brown, too rich for the speed but not too bad. Would like to have all four the same colour. Think I will go after air leaks first. The O2 reading bounces a lot.

The closer I get to having the FI system sorted out so I can get it out for a road test, the little things are coming to the fore. Adapting old to new is a challenge.

 

[Rednaxs60]

Have the MRS siblings in town because her brother passed away two weeks ago. Celebration of life on Saturday. Everybody is in good spirits.

Hosting one of her siblings. Had the brother-in-law out In the garage for a show and tell. Went pretty well. I mention the need for a vacuum leak rectification. Demonstrated to her brother-in-law how the new ECU works and what the tuning software does. Mentioned that there are vacuum leaks. Sprayed copious amounts of quick start on the mating surfaces between the injector holders and the cylinder head/air chamber. AFR gauge went hard over to max rich condition. This happened on both sides. Next item to correct when this weekend is over.

Checked with the local Honda car dealership for the required o-rings. Available but are $6.00 CDN each, need 8 - ouch. Will look at a couple of alternatives first. Will also use Honda Bond 4 on the mating surfaces as well.

 

[Dusterdude]

Red,what is the part number(s) on the o-rings?

 

[pidjones]

For most o-ring applications on our bikes, Buna-N (nitrile) is fine. Viton only required for high-temp areas (>100C). Even Harbor Freight (Princes Auto?) Has kits that have good variety, and Amazon has even wider selections.

 

[Rednaxs60]

P/N 91301-MG9-003 Size 35.2 by 2.6 mm. Thickness is the key issue for sealing.

Princess Auto has a metric o-ring kit, 419 pieces, for $22.00. Trip there is in order.

 

[Dusterdude]

Those are motorcycle dealer available only

 

[Rednaxs60]

Those are motorcycle dealer available only

Thought so as well, but the Honda car dealership said it can get these out of Edmonton Alberta.

Did get an o-ring kit from princess auto. The o-rings that are the closest need a bit of stretching to fit the air chamber o-ring groove. Have done one side and it is an improvement.

 

[Dusterdude]

Groovy

 

[Rednaxs60]

Groovy

No pun intended!

 

[julimike54]

It looks like CMS has them....

https://www.cmsnl.com/products/o-ring355x26_91301mg9003/

 

[frankroche]

I bought o rings from an online site. i you have the dimensions (found on online Honda parts list). Had to buy (I think) 10.00 worth. Very inexpensive. Just Google o rings for sale

 

[pidjones]

You can also buy o-ring stock and glue up your own.

 

[Rednaxs60]

Have installed new o-rings from a kit, had to stretch a couple. Would like to get some o-ring stock of approximately 2.8/3.0 mm thickness.

Adjusted engine timing as mentioned. Do the initial timing (trigger angle) before engine start and the engine does not like the setting. It is less than the base 260 TA at 245. Start the engine and increase trigger angle to 274/275 and the engine likes this setting. The marks I have on the trigger wheel for #1 TDC are more user friendly than trying to get at the crank timing marks. The crank timing marks are preset and not in degrees.

Using the new TA value(s) and with the new o-rings in place, have the engine idling in the 1000 RPM range with some fluctuation. Will be looking into this. The better and smoother the base idle the sooner I can move on with the engine tuning.

The plugs are a good colour, bit rich but much better:


It's a balancing act at this time. The fuel enrichment tables are being adjusted to get a good start.

As I get closer to a stable, smooth base idle, it is a balancing act of settings/values, and tuning of the various features such as dwell/spark settings.

More to follow.

 

[pidjones]

I get my o-ring cord on ebay from vendor professor foam. Search "professor foam cord".

 

[julimike54]

@Rednaxs60 Are you using new plugs for every test run involving plug color? Are you cleaning and reusing plugs?

 

[Rednaxs60]

I have 6 sets of plugs that I reuse. Use a small propane torch to clean, gets down to the bottom of the porcelain. I use one set of plugs per day at this time. Old school cleaning with a wire type brush doesn't work as well, nor is it recommended. I compare the plugs to determine what is happening.

Changing tuning parameters and letting the engine stabilize is quite quick with an FI system. Changes are noticed very soon after a change is made. If the change is beneficial, I keep, if not, I change back to what the value was and pick a new value.

The cold start fuel enrichment tables are being tweaked. This engine seems to want more fuel on cold start then what the tuning software tables start with.

The coil dwell seems to be a bit different. Hard to tell if a change of a millisecond does anything. I leave these change(s) in vogue for a longer period of time, same for the spark duration.

@pidjones - thanks for the info.

Don't think I have the air leak situation 100% in hand, but will accept the 95% solution at this time. Could be the throttle plate linkage, or one of the other connections. Honda has the FPR connected to ports on the air chamber.

The MAP reading stays at approximately 60/65 Kpa. Thought it would be lower around 20 to 40 Kpa at idle. Going to research this and determine if anything can be done. The MAP sensor being used is a 2.5 Bar MPX4250AP.

Using the trigger wheel for timing corroboration is much better than trying to use the engine case timing port. I am able to cross reference engine timing between engine and ECU much easier. The only issue is the timing light and having to remove the left side timing belt cover. The degree reading on the timing light to determine advance timing degrees has to be divided in half.

 

[Rednaxs60]

Another trial day. Made a timing mark pointer, works well:

Confirmed that one tooth and one valley equals 10 degrees, this makes the trigger wheel an exceptional timing degree system, easy to use with timing light.

Seems I will be staying with a base MAP reading of 60 to 65 Kpa. Going to have to accept this.

Adjusted the spark table values and curious about the values. The values in Tuner Studio (TS) are quite large, in the 48 value range at an idle of approximately 1000 RPM. Thought these were to be degree advance angles. Checked with timing light and the timing advance is roughly half of what is in TS.

Still have the engine stumble. Reviewed the data log and notice that every engine stumble coincides with a fuel reduction, no indication of an electrical fault. Don't think spark is an issue, engine will operate not the best with two cylinders not firing, but no fuel will cause the engine to stumble/stall. I have three fuel pumps to use, one OEM and two aftermarket. Have tried the OEM and one aftermarket, will try the last one to confirm hypothesis. Trying to get to the reason for the engine stumble.

I do want to get the spark table values down a bit. Going to use RPM and spark table values and determine if I can get a stable, smooth idle, increase RPM - decrease spark table values. Might work?

Time to start getting the bike wiring cleaned up and get the plastic back on.

Still pondering sequential fuel injection.

 

[Rednaxs60]

Have the engine timing put to bed. Reviewed a lot of forum comments, and went back to what I started with.

Reviewed Honda's design timing on the spare engine last night and everything is exactly what it is supposed to be. Reviewed the initial TA against the install of the 36-1 trigger wheel - GIGO applied with this one, was using a TA of 260, should have been 270, now corrected.

Cold Advance set to "0".

Reworked the spark table to initial values.

Locked the timing at "0" degrees, set timing on engine. Unlocked timing and used 20 degree cranking timing, no move of the timing marks. There is a relationship between the locked timing value and the other values, was not aware of this. Redid the timing with the cranking timing value and locked timing value at "0". Significant change in where the timing marks were. Reset TA to 267. Checked cranking timing of 20 degrees with timing unlocked, timing mark at 20 degrees. Put this one down to an understanding of how things work, especially software.

Started engine nicely. Will have to adjust for cold engine start, but now can do this.

Checked engine timing at various intervals when I adjusted the spark table values. Timing mark adjusted as well to the value set.

AFR and VE table values are not too bad.

Checked plugs and like the colour.

Timing is finished, maybe some tweaking, but timing is done.

The OEM idle spec is 1000 RPM +/- 100 RPM. Checked idle timing with a trigger wheel degree circle on the crank, approximately 14 degrees BTDC from what I can tell.

Still have an engine stumble, but think this is a tuning issue.

Will be cleaning up the wiring, get components secured, and putting the plastic back on.

 

[Rednaxs60]

Thanks for the "Likes". Timing is an issue with all early model GWs. Trying to get at the timing mark port with a timing light is not the easiest. For the non-electronic ignition GWs, would recommend a thin degree wheel - doesn't have to be thick, be installed, sandwiched between the crank timing belt pulleys. A small timing mark indicator be installed on the case. Mark #1 TDC, and some reference marks to determine where the timing degrees. I'd come in from the left side. I've read several forum posts that are related to engine timing.

The timing indicators that Honda uses are exact. "T1" aligned with the cam shaft pulleys, gives an exact position for #1 TDC. The "F1" crank mark for idle timing is approximately 14/15 degrees BTDC, good idle timing.

This would be a peace of mind project because there is no way to adjust the timing on most GWs.

Timing light is another consideration. The older timing lights like the one I have is, a Snap-On MT241A - still a good timing light, is not designed for a wasted spark system. It has a degree dial that is not recommended for use, but when set to "0" degrees, works just like a timing light without a dial indicator.