| Author | Message | ||
     Buellisticx1 |
Hello everybody. My setup: -1250 kit/hurricane forged pistons, 10:5:1 compression (NRHS) - Stage 1 porting heads.(NRHS) - Race ECM tweaked with ECMSPY - O2 OFF. - WOT enrichment 115. - C.F. oval air cleaner from Al American Sport Bike. - 2.5" Stock header and D&D muffler. I'm having an issue just on 2500 rpm range. As soon as I roll the throttle it stutters. Very irritating. If I twist the throttle quickly the bike tends to bog. It just happens in 2500 rpm range. Slow twisting works just fine. The behavior is more pronounced in lower gears. The bike runs great and and feel a solid increment in torque and power (midrange and top end). I'm pleased with the way it runs, except in 2500 rpm range When I try to give it some gas real quick to bring the revs up. I thought May just be the characteristics of the D&D pipe, they have less low end but better midrange and top end. I know Adding fuel blindly is a sure way to screw things up. In many cases, it will have the opposite effect. My question is "adding fuel helps the condition?....or on the contrary "reducing fuel"?... Can someone guide me to what I need to do? (Message edited by buellisticx1 on September 25, 2009) | ||
| Oldog |
My bike does that too with the street ecm Not sure about the race unit | ||
| Kalali |
Why do you have the O2 sensor off? The only time I know you need to turn te O2 sensor off is when you are tuning the bike on the dyno and trying to set the air/fuel ratio to anything other than 13.5/1. After that you should turn the sensor back on. If it were my bike, the first thing I would do is turn the O2 back on and see what happens. Just my 2 cents. | ||
| Buellisticx1 |
Had my bike tuned with a wide band system on dyno with surprising outcome. So on the first run it made about 93.6 HP and 107 Nm (WOT enrichment in 110%) at the rear wheel, and the second run increasing the WOT enrichment to 115% it pulled 98.6 HP and 114.3 Nm at the rear wheel. Torque peaked at 4300 rpm and HP peaked at 6900 rpm. The dyno tuner said me that With the O2 off the bike has more torque and power in closed loop area. He increased all the values by 4 in all cells in closed loop area for get a AFR of 14:1 and not 14.7:1. to more richer and now it runs a better then before. With this setup you get a solid increase in horsepower and torque in midrange. The tuner also increased the RPM limit at 7000 rpm and he recommend me 7000 limit RPM as a safe RPM limit. My engine is loving this setup. With the O2 on/off, it doesn't says anything about the stutters issue when rev up from lower TPS. The chart shows the torque drop between 2200 rpm and 2700 rpm. and the tuner said me that's fairly typical behavior on Harley-Davidson V-Twin Engines, but this seems really odd to me. Can someone guide me to what I need to do?.... Sorry for my English but I´m no native speaker. (Message edited by buellisticx1 on September 27, 2009) | ||
| Natexlh1000 |
Look for a chafed wire above your engine, under the fuel tank. It may be rubbing at a specific RPM due to the engine's rubber mounting system. If you're lucky, your problem could be fixed with some electrical tape. | ||
| Buellisticx1 |
Ok!!, will do, but the problem doesn't intermittent. The problem just happens at 2500 rpm, not 2000 rpm or any other rpm. Have you ever had this happened with your X1?.... Thanks for your input. | ||
| Buellisticx1 |
Here is a dyno sheet with three runs. The first run in blue color (WOT ENRICHMENT AT 110% AND O2 ON), the second in red color( WOT ENRICHMENT SET AT 115%) and the third runs the color is yellow (WOT ENRICHMENT SET AT 115%, +2º TIMING ADVANCED AND O2 OFF). Numbers in left side of the dyno sheet are a bit wrong but you can get an idea of what I'm saying (torque drop between 2200 rpm and 2700 rpm) All the runs below are made at the same engine temp, 170C.  | ||
| Kalali |
This may or may not be related to your issue but I recall seeing a couple of dyno charts for stock X1s both showing a drop in torque around 2500-3000 RPM. The drop basically disappeared with an aftermarket exhaust and race ECM. I don't remember which exhaust. My personal experience with V&H and race ECM confirms a more linear torque delivery in that RPM range. Of course my bike is nowhere as powerful as yours. | ||
| Natexlh1000 |
>>"Have you ever had this happened with your X1?" Yes but now as I was remembering back, it threw a code. "front injector" It was still under warranty so I brought it in. The shop found that a wire had worn through to the front injector. They heat shrak it and it's been fine for 50,000 miles. but I guess yours isn't popping the engine light on... | ||
| Preybird1 |
You are going to need to see what the fuel cells are doing at that rpm to figure out what is going on. You need ECM spy to view the fuel maps and if the your builder\tuner cannot adjust the fuel and timing in the maps them selves you are in the wrong shop. The fuel and timing can only be adjusted by going into the maps and changing the cells. | ||
| Yo_barry |
I've got a stock engine with Race ECM. I still get a little stumble 2500-3000 RPM when cold but not when it's warmed up. Check for a vacuum leak -- specifically a nipple on the bottom of the throttle body that used to be connected to a carbon filter. Plug that nipple with a cap or hose/screw arrangement. The other place where you could have a vacuum leak is the manifold to head gaskets and the manifold to Throttle body gasket. ymmv | ||
| Buellisticx1 |
Ok Yo_barry, I got plugged the vacumm port of the throttle body. There isn't any intake leak. The intake seals are new. I get exactly the opposite symptoms on my X1. I get stumble 2500-3000 RPM after it's warmed up but not when cold. I suppose it will be by richer mixture at cold start enrichment. These are the images of my Eeprom. At 2000/2500 Rpm the AFR was set at 13.5 (front and rear). Maximum engine torque occurs at about 13.2 AFR under (WOT) condition at 4000 Rpm and Top End was set at 12.8 AFR (WOT). FUEL MAP FRONT  FUEL MAP REAR  OTHER MAPS (WOT/ REV LIMITS/COLD ENRICHMENT).  O2 OFF.  Thanks for answering. (Message edited by buellisticx1 on September 28, 2009) | ||
| Preybird1 |
How was this bike tuned? Single O2 sensor on the existing pipe using an Eddie dyno or equivalent? What about the front map, Was there a second O2 sensor in the front while tuning the front map? It looks like the maps are not similar enough to each other in the cell numbers. (I AM NO EXPERT) Call Terry @ JTS performance. Also here is there e-mail info@jtsperformance.com | ||
| Buellisticx1 |
I took out the stock narrow band and it have been monitoring with a Wego 2 wide band system on front and after on the rear. I welded a bung on front pipe. They used a DYNOTEST dyno. I asked the guy if there is a correction factor he told me that it was actual rear wheel HP and TQ (Norma CEE not SAE). On the chart above you can see the torque drop at 2500 rpm range. I thought may just be the characteristics of the D&D pipe, What do you think about?... The tuner said me that's fairly typical behavior on Harley-Davidson V-Twin Engines on 2500 Rpm range, but this seems really odd to me. The main problem is that in Spain where I live here there is not too much knowledge about tuning buell's on a Dyno, just bikes Japanese although. I emailed several times to Terry @ JTS performance two months ago, but they never no response.- also I started one post in his section of BadWeB sponsors two months ago looking for an answer with no luck, no response yet. | ||
| Kalali |
On the ECM Config page, do you have "Idle Closed Loop Enable" box checked? How about "Open Loop Learn Enable"? I personally have never run the bike with the the O2 sensor turned off but I am sure the sensor has a great affect on how the bike runs depending on the status of those two selections. One simple experiment you could run is trying to play with the fuel cells in the closed loop area (the cells inside the red zone on the fuel map) and see if adding/reducing fuel makes any difference. Of course you should save your current maps before you do anything. Having said that, in my opinion, if the bike runs great with the exception of the drop in the 2500 RPM area, the exhaust could be your culprit. | ||
| Natexlh1000 |
What about trying the "Race ECU" map? Just as a temporary thing to eliminate other possible factors. | ||
| Buellisticx1 |
I tried it with no luck Race ECU" map is very lean for my setup. One other question; Could be the Torque drop shown in the chart above related with my problem?, I think so and you?..... | ||
| Buellisticx1 |
SOLVED!!!. I managed to get rid of the stumbles. Already there is not stumbles at all. I set Accel Rev in 3 value and Accel Enrichment to 25% in 2500 rpm, With this setting my X1 has not stumbles at all. Here is the link if you want to look read it. http://www.buelletinboard.com/forums/showthread.ph p?t=11807 I just want to thank you very much to Gunter, gbalias and kalali members from BuellinBoard Buell forum. Thanks buellers for your help. Best Regards Buellers! | ||
| Kalali |
Jose, glad to hear the good news. With all the modifications you have done to your motor, your bike needed a larger dose of fuel (in certain areas) as compared to most if not all the lightly modded bikes, including mine. And the fact that you are running your motor in Open Loop all the time requires a greater deal of importance in the accuracy of the fuel maps, specially right where you were experiencing the stumble (normally Closed Loop with the O2 sensor). Enjoy. P.S. I thought you ended up with 30% enrichment at 2500, up from 25%? | ||
| Buellisticx1 |
Hey kalai, Did you solve your problem with the Accel Enrichment on your eeprom? I ended up with 25% enrichment at 2500 and full accel revs to 3. Now when twist the throttle quickly from very low rpm the bike does not any stumbling at all. Accel pump was low.... Thanks to all who responded and added their suggestions for what might be my issue. Regards. | ||
| Natexlh1000 |
That's really really great! | ||
| Kalali |
When I changed the accel enrich revs to 3, the bike would stall at the slightest application of throttle. So I ended up changing it back to 1 but had to use your method of doing it right in the EEPROM table. It worked and all is well now. My "stumble" was/is very subtle so it really does not bother me but I just wanted it to be perfect. May be I will try upping it to 2 and see what happens. The lesson we learned here for everybody who plays with ECMSPY is that the acceleration enrichment revs (in the Other Maps page) acts similar to the accelerator pump in a carbed bike. The higher the number of revs, the more fuel is "pumped" when you twist the throttle quickly. And the table right below it (showing RPM and enrichment %) allows for fine tuning the "pump" action at various engine speeds at a specific %. | ||
| Buellisticx1 |
Glad to hear you could fix it. I completely agree with you.. The fuel map is timing, fuel, WOT enrichment, Accel Enrichment, etc.... |
