ECU Map and PVC with AT

Hi All

Had a problem this week, typically it was as I headed off on holiday this, i should have left things alone but it got me to thinking.

For some reason I reset my TPS and stepper motor, checked my ECU map then accepted the trims on the PCV AT. I have the POD300 that displays AFR etc but took it off as I only have one mount and wanted this for the radar detector. On the day hopped on bike and off I went bike ran like a dog, hesitation on throttle, backfires, unstable at low revs. Plugged in my POD as I had it with me and bike was running very lean at low revs. Acceleration and load was fine. Once riding for a while the problem sort of went away but stop and start again it came back

I solved the whole issue by reloading Hanso's (The Legend) base PVC map he sent me and all was well.

So here's the question and how I think i got to this issue.

I'm running the Autotune and its targeting an AFR value that we set in the map and its making trims to the fuel injection that we accept and then make permanent. If I am riding long distances and the bike ECU is jumping between the F and L tables this is going to mess up the fueling correct? as the ECU will be changing its injector pulse timing but the PCV wont know this and applying its trim to it as its simply trying to get a set AFR on the O2 sensor.

Should I turn off the FL switch when running the AT so effectively there is only one table the AT works with?

(If you accept AT-trims in PC5, you will also have to push the send-button. Otherwise there is no change and all learned tables are gone.)
The AT just works with a TPS-table. But It does not care what goes on in the ecu. It worked satisfying before.
The map sensor should at least work up to 5% throttle openening to let it run smooth at low load.
Probably something went wrong when you did the tps-reset.

The F/L switch values are that - a switch. The thing is to move them away from your cruising throttle opening values. Thus it will not be switching when cruising.

The AT does not know if you're in F or L - it just moderates fuel to the AFR values you want. If, however it is not having to compensate for switching - the sampling will be more consistent - so the trimming will be too.

The F/L-switch is not a real switch.
There is a "transitional area" of a few % that will make it smooth.
Only if one of them, the F or L table is far off you will feel it switching.

Hi Penner

Thanks for replies, got it on the sending to the pcv. Also understand it's not really a switch.

The issue I was encountering was a leanout right on the table change where for a while I would get 16 to 19:1 AFR. this only occurred after my last trim accept and send.

I think the issue was that during normal motorway speeds here (100kph) the TPS is just above the F/L switch point and when it switched it leaned and stuttered but cleared and AFR came right the second the bike was on F table as more fuel goes in from ECU. Like all things it doesn't like sudden changes.

Thinking I could avoid this by turning off the L tables, only running F tables and letting the PCV and AT do it's job and trim based on measured/targeted AFR.

Reset the PCV to blank table and issue went away. Do not like this as I know I just got rid of the problem didn't understand and resolve it but when your on site of road in the other island,in the sun and its 35degC with your bike plugged into your tablet it works.

Just want to learn from this.

Thanks for input so far keep it coming please.

barbagris said:

The F/L switch values are that - a switch. The thing is to move them away from your cruising throttle opening values. Thus it will not be switching when cruising.

The AT does not know if you're in F or L - it just moderates fuel to the AFR values you want. If, however it is not having to compensate for switching - the sampling will be more consistent - so the trimming will be too.

Click to expand...

Thanks Barbagris

As my reply to Penner the AT does not know what table am in but they are two tables with different air mass volumes and when it switches think it catches the AT. Like all control it can only react to a measurement so if the ECU switches suddenly say from F to L there is a sudden drop in fuel going in if the L table has a lower air mass value. Think this where the stutter and leaning occurred as the AT needs a second to react.

Think had pushed the fuel trims too far so cleared and started again but would have rather had more time to experiment.

Guys please feel free to correct me if my replies and understanding of this are fundamentally flawed I will not be offended.

Andrew, I've spoken about this "surging" problem that I've been experiencing with the bike, for you Guys out there it feels like if the bike had a chain drive that the chain was tight then loose.
First off I thought it was the rear brake not releasing properly, there was problems there which I have resolved but the problem persists.

What is happening is when cruising the bike "surges" but what I have realised is that this surge is power dropping off.
All is fine until I have about 15Km on the bike, meaning that it has warmed up.
Decelerating there is no backfire or anything and it accelerates just fine. (when this surging is happening, I can give it a heap of throttle and it responds as I would expect, no missing, no mucking around)
What I am now thinking is that either a plug is breaking down or a coil is loosing it, as I say the feeling is of the power dropping off then regaining.
I've bought a new set of plugs but as yet haven't fitted them, have checked the low tension terminals on two coils, the front one was too hard to get at in the state of mind that I was in at the time of doing this, so it still could be that one.
If after I have changed the plugs and the problem persists I will start swapping out the coils, one at a time to eliminate that.

BUT !
Could this problem be anything similar to what you have experienced ? You knowing what Map etc I have.

Sleeves I’ve observed the same behavior using the AT. I've also observed my AT O2 sensor to exactly match a very expensive Dyno o2 sensor at 14.7:1, but read a half point off at 12.5:1, it reads too lean so its off, but its off the safe direction.

How I fix it is:

Adjust your FL table switching points similar to this:

The reason, is that like you say, when cruising, even on the freeway, your below 10% throttle. As @Penner mentioned, the "switch" isn't really a switch, its a influence curve. Even up at high RPM where the FL Switch table is 0, there is still some influence from the L table, in particular during throttle position transition, such as when you go from steady state 8% to full throttle, it uses the L table to influence the acceleration enrichment.

Now, for the auto tune to play nice here is method one:
Load a base map that you KNOW is too rich everywhere, cool, now you're just trimming fuel out. Go into the Autotune properties in Powercommander software and adjust the control from 20/20 enrichment/enleanment to 5/10 enrichment/enleanment. It's honestly, quite unreasonable to be at 20%... too much authority from the algorithm. Go ride for an hour, try and hit as much of the table as possible, so you're getting good data for it to adjust against. When home, accept trims, reduce the autotune authority to 2/6 enrichment/enleanment, and go for a ride, use your pod300 to datalog. Download the log as a csv file and use megalogviewer to check your AFRs from the datalog (its the most friendly software in my opinion for log viewing, much much better than the PowerCommander software for log viewing). They should be really good, if they are:
DO NOT ACCEPT THE AUTOTUNE TABLES AGAIN. Adjust authority to 5/5 and leave it be. This way, the adaptation it's making is small, and the map is already really close to right so the adjustments don't need to be big, they will account for elevation/baramoter/gas quality changes only, which is what you want.

The autotune isn't good ad zering in on a "perfect" fueling adjustment value. This is exactly why i bought the POD-300, because the AT gets close, with about 0.5 AFR of target, then I data log and manually adjust it to "just right" and leave the AT with 5 enrichment and 0 percent enleanment authority.

There is another step I suggest. The autotune is honestly pretty **** at adjusting the low load areas, the L table areas. To fix that, you do this with the target afr table (all 13s were just so i could show it to you real quick):

When you set it up like this, its only adjusting the F table area, and you manually adjust L table area.

The reason:
L-table area is best tuned by feel not AFR. its the area you're doing the "delicate" riding in, parking lot, slow speeds traffic etc, so it needs to feel right, AFR be ****ed. If it wants to be rich to be smooth and torquey... fine, if it wants to be at 14.7, fine, it doesnt matter, those areas will never hurt your motor unless you doing something really dumb like try and run at 18:1+ afrs or 10:1 afrs.

Hope this helps, the autotune is a great tool, but its not perfect.

@Paul Bryant The surging, I've also experienced, is the autotune hunting for the right AFR and doing it badly, resulting in lean > rich > lean > rich swings. The solution is a base map that's already pretty close to correct (hanso's or one of the others) and using the autotune with reduced control authority as I outlined above.


EDIT: ALSO, remember these tables are only points on a large 3D graph that the computer interpolates from the table values, so, for example, while it is 0% on the 10% column, it will still adjust slightly at 11-14% (in a tapered manner from the value in the 15% column down to 0% at 10% column).

Also, speaking with the PC tech dudes, they tell me, if you rev higher than the table goes, it just stays at the max value, eg the 7000 RPM values once you go outside the table.

FINAL EDIT: When riding for an hour to train the AT. Try and do full RPM sweeps at static throttle position. So like, at 2k RPM open it to 30%, hold it at 30% all the way to redline in a single gear. Try and do this in 4th or 5th (yes i know it means you'll be going ****ing retarded fast). Do this for 30/40/50/60/80/100 percent but try not to trigger accel enrichment, so open the throttle at a moderate pace from cruise to the target percent. It's hard, but it gives the AT clean data to work with. Using some bake brake to slow your rate of acceleration is a good thing, it'll give it more data points to use to tune against.