Closed Loop Idle Question

[lawdog]

Sorry. I should have proofread. My bad. Yes AFV won't change until the bike is in closed loop learn. The bike will apply the EGO correction continuously while in closed loop as it reads the O2 sensor and adjusts the fueling to maintain 14.7 AFR. It will then change the AFV while in steady state cruise matching the rpm/tps for the closed loop learn area of the map. It will then apply the global fuel correction and adjust the AFV to get the bike closer to 14.7 AFR to have smaller EGO corrections.

Good catch!

 

[WiredForStereo]

Lawdog, I'm confused too. That's why I am asking questions. So far, no one has been able to answer them sufficiently, just a lot of assumptions of what I have done to screw up my bike (all of which have been false).

I have asked over and over and over repeatedly for some advice on how to tune idle, and nobody answers. What can I do but ask again?

I ask, and literally, I get nothing. Does anybody know how to tune an idling bike around here? The best I've been able to do, all on my own, is to keep the bike's idle higher until it warms up. Nobody has a better suggestion. I'm not stupid, I just need the information to work with and nobody seems to have it.

 

[lawdog]

Of course. I will help you any way I can! Ok so can I get some basics. Year, model, mods, and what you changed in the EEPROM.

Also tell me how does the bike idle when first cold start? Cough, spit sputter, backfire, high idle, low idle, stall.

Then how does it idle when warmed up? Any changes between cold idle and hot idle?

Is mechanicals solid? Runs good otherwise, clean spark plugs, good battery voltage, strong spark, fresh premium fuel, etc..

(I am trying to narrow it down between closed loop or open loop or what correction may be screwing up your idle)

-Brett

 

[WiredForStereo]

Lawdog, thank you for your time, I really appreciate it.

2008 XB12XT, K&N (previous owner), Muffler modded to front exit (me). Will do a write up on it at some point, haven't yet. Basically, I put in a U pipe at the back so it's a straight pipe all the way to the front chamber where the exit is. The internal perforations in the center chamber are capped over. Bottom center through tube is capped at the back. Breather mod done (me). In the EEPROM, I have only changed the fuel maps, the idle air control table (and flag) the AFV for tuning and I think that's it. I saved a copy after each mod.

Mechanicals are solid, no more loud mechanically than any Harley. Battery fine, assume spark is good, brand new iridium plugs, premium fuel, had preserver in over the winter, but ride regularly and so relatively fresh. Just filled it Sunday. Amsoil 10w-40 motorcycle both holes currently. 13,250 miles. Purchased last Thanksgiving. Just replaced the seals in the left fork, replaced fluid in both, Amsoil #10.

Before I changed the ECM, it started and ran normally. Occasionally, right after starting, it would just die, but restart would be fine. It has always done that, probably one in ten starts.

I followed instructions of posters here on how to tune with EGO Correction on logged rides. Incidentally, the first time I looked at the ECM, AFV was at 73. High altitude, longer pipe, kinda expected low numbers. Did about half a dozen rides, all went well, fixed dead spots. Idle set to 1000. Got the values generally within +/- 5% except at 4000-4500 RPM WOT where there was a dead spot and I added fuel there until butt dyno said was fine.

After that was all done, when cold, it would sound like it was suffering in idle, coughing, dying. I could hear the idle air control valve opening to allow more air, but it sounded like it wasn't getting fuel to go along with the air. There was some chuffing out the intake, coughs, etc. The sort of behavior that's embarrassing in a parking lot while you're trying to put your helmet on. Hitting the throttle made it run fine. Riding cold wasn't good either, wanted to cough and jerk a bit, had to give it extra throttle to get going.

When I log it warm, the EGO Correction stays right around 100 (+/-5)for all cells. And as I state above, when warmed up and in closed loop idle, EGO says ~110. Also when warmed up, it idles very smoothly at 1000 with only a little variation. It runs, I'd say perfectly when warm, but I've never owned another Buell, so it's hard to compare. I've ridden it about 1000 miles since I bought it. I've ridden my brother's a few times, but I don't know what was done to his ECM so I can't compare there either. There is some decel popping though it's not bad or objectionable.

I had set the Idle air control to drop to 1000 at 60C, and that's where the problem was most apparent. I now have it set to drop to 1000 at the next step up, I forget exactly what temp that is. So when I start it, it starts at 1500 and drops at each temperature interval until it gets to 1000 when it's plenty warm. If I remember correctly, I also have the fan set to kick on at right about the same point when idling, at 160C I think.

I have a thermometer dipstick. Normal operating temp is 90C.

Back in March, I did dump it on a dirt road after hitting a mud puddle. Broke the mirror, hand guard, front brake lever, turn signal, and my foot. Everything repaired except my foot which is still hurting.

If there is any other information you'd like, I'd be more than happy to give it to you.

 

[ReadyXB]

Sorry. I should have proofread. My bad. Yes AFV won't change until the bike is in closed loop learn.

I figured that was the case, as you seem to know your stuff.

 

[lawdog]

I would lean towards the fuel map at idle is off (need a wideband to check), or tps reset is in order. (Barring of course any other mechanical issue.) Your AFV might be off as well. If you are having trouble in open loop, you may be rich/lean until you go into closed loop and the bike can compensate. Again a wideband will tell you such. You can try going for a cruise and get into closed loop learn and see if the bike can get your AFV inline. But if it were me I would throw on a wideband to see what the bike is really doing. Otherwise we are guessing.

Here is a decent thread on tuning. If you wanted to live dangerously you could starting playing with your warmup enrichment but I think that is a bandaid for the real problem of not having a wideband and knowing what the bike is running.

Pickup a Zt-2 wideband with a black bog logger or other logging device of your own.

 

[WiredForStereo]

So, contrary to what I've been told, you CAN'T do a decent tune with stock equipment?

Well, that sucks.

Wish people would have been a bit more honest about that before I started.

All this nonsense about datalogging and whatever else and it turns out you can't actually tune where you need it most, sitting next to your friends in the parking lot.

 

[WiredForStereo]

Let me approach this from a different direction. If there were a way to fix this with the equipment I have, how would it be done? What is the solution?

I know the bike runs right otherwise, I just rode it 1100 miles in 36 hours. Why is the idle so hard to tune and why are there so few answers?

 

[WiredForStereo]

And if I decided to drop the $300 for the ZT-2 and go with wide band, how might I do that? Will that O2 sensor fit in the existing bung? How difficult is the wiring? Would it be worth it? Would it be more economical to use a heated narrowband sensor and would that change the results at all?

 

[lawdog]

Here is my personal opinion on tuning with the stock NB O2 sensor. You can get your bike to do a great job meeting emission standards in closed loop operation using the stock sensor! Ok that may be a bit sarcastic as the idea is the base map of the bike is close enough and you fine tune your closed loop region using the stock NB O2 sensor; then your open loop areas will hopefully be close enough to work. In all seriousness you can tighten up your closed loop region by datalogging and tuning with the stock setup but you still don't know what the bike is doing in the open loop.

Then if you make drastic changes to the motor such as intake, exhaust, etc then the base map may be way off. Some guys will upload a race map and run with it and it works. Some will buy an EBR ECM, or get a map from Mike Cobb.

A wideband allows you to tune all areas of your fuel map. Open loop, closed loop, WOT, decel, etc. You can either datalog and run one yourself or take it to a dyno and pay a shop to do it.

With the ZT2 you remove the rear O2 sensor and install the wideband. You tap into the coil and tps wires to datalog. You turn off closed loop in the bike, lock the AFR to 100% and datalog. Make changes to your map to get you 14.7 in closed loop area and 13.2 into WOT. Make same percent of change to front map as you did the rear map. Remove wideband, turn closed loop back on, sell wideband back on ebay to recoup money.

I welded a bung on my front O2 to datalog it but I am in the minority.

A heated o2 sensor just gets you into closed loop faster but it may still run poorly until you go into closed loop.

I would say you have several options.
1. Live with it because it gets complicated from here.
2. Pay a dealer or indie shop to tune it with their WB on a dyno.
3. Play around with the idle area of the map and maybe you will get lucky and get it right. ( I would start by adding 1 and go from there)
4. Turn off closed loop all together and just lock out the bike to run richer across the board.
5. Install heated 02 sensor and live with crappy cold start until bike goes into closed loop idle.
6. Dive into the world of wideband tuning it yourself.

For reference I run a ZT2 with pocketlogger on a palm pilot. Upload the datalog to my computer, interpret with winlogview, and make changes in the Hexdata using excel spreadsheets. It is not user friendly and old school. I would recommend datalog with ZT2 and make changes with Tunerpro or Ecmspy if you go the DIY route.


Here is a datalog I just did several hours ago. Installed Big Bore Kit. Locked out my O2 around 110% fueling to be rich and safe. First ride down the street and back. This is the front cylinder. I am not tuning yet but just wanted to make sure I was running a safe AFR while I am doing my break in.

 

[WiredForStereo]

I spent last weekend riding down to Albuquerque and back. About 16 hours total riding in 40. The bike performed well, even batter after the AFV kicked in. Spent a total of 12 hours at highway speeds, upwards of 80 mph. Performed outstandingly in those conditions. Top speed briefly at 130 or so. Turns out the bike is quite a bit more stable with the bags on. Operating temperature didn't exceed 95C, even when trying to plow my way through sand in first gear out in the desert. Don't do it, you wouldn't like it. This thing does not do well on sand. And it's really heavy to pick up. Glad I don't have a Harley trying to do the same thing.

Had a little trouble idling, but doesn't die as much anymore. Also coughed a few times when riding after starting up warm (after sitting for a few minutes but not cold).

I don't need super performance. In fact, all I really want is 14.7 AFR. I'd take fuel economy over raw power. I'm not racing anybody, just touring and some twisties. I'm wondering about modifying the cold idle enrichment, any thoughts on that?