Someone please help me understand AFV (using ECM Spy)...

Started by x1rider, July 02, 2010, 06:31:31 AM

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x1rider

The bike is a 2002 X1W with ForceWinder intake and big bore Force exhaust. When I put it back together, I put new exhaust gaskets, I changed the intake seals, injector o-rings, I put a new head temp. sensor, new O2 sensor, new fuel filter, and I checked the air temp. sensor's resistance and it is fine (also monitored its activity with ECM Spy).
I removed the PCIII I had on, following advice from this forum, and reprogrammed with the Race ECM using ECM spy. I did the TPS reset and set it at 5.1, and reset AFV to 100%.
I use NGK DCPR8E plugs gapped at 0.040.
I took a ride yesterday, did about 8 miles, let it cool off a few hours, then 8 miles again. The bike won't idle (even after the first 8 mile ride, it stalled as soon as I let go of the throttle (I managed to get an idle at around 1000rpm with the TPS at 8.1). Anything 3500rpm and under, the bike hesitates, sputters, and spits through the intake. During my 8 mile rides, I kept the rpm at about 4000 (because it didn't run well below 3500rpm), and speed around 60mph and it ran OK, but no "kick" when trying to accelerate quickly.
I checked my AFV after coming back, it was down to 81.3%. I removed the plugs and they are gray/white. I used a propane torch and sprayed propane around the intake flanges, no raise in RPM (I did the test with the engine hot, I'll try again with the engine cold). I contacted Mike Cobb and he said a low AFV means the bike is asking for less fuel. I don't understand why the bike is asking for less fuel when the plugs indicate that it is already running lean.

Any help or comments on this situation would be greatly appreciated.

Should I just add fuel to the whole fuel table and try riding again, see how it will react? I'm at a loss here, I never had those issues with the PCIII.

Thanks in advance.

Here are a few pics of my X1W after I put it back together (I did some black powdercoating on various parts and did a dual headlight conversion)



Pushrod

Did you diconnect the O2 Sensor before  tuning?,

if not  the AFV will reset the AFR to 80% when enteing closed lop mode to reduce fuel and try and get the default 14.7AFR


x1rider

I didn't do any tuning (I plan to eventually get it done right on a dyno), I just flashed the ECM with the Race ECM eeprom.  I reset the AFV to 100% but it keeps going down and leaning itself out.
I did further investigation and it seems to point toward a bad ECM.

jbee

Hi x1 rider,
I see it was a while when you posted and I hope you sorted your problem out.
Great work on your X1, it#s good to see an X! in such fine condition, Are they still standard tyres ? You might get even more fun out of your bike if you switched to a sportier compound :wink:
If you are still having issues here are a few thoughts..
1) Before you set your TPS at 5.1% you say you reset the throttle,by this I take it you reset/zeroed the throttle to 0% by screwing in the idle adjust screw, reset to zero electronically and then set the TPS to 5.1%.
2) If the AFV is resetting at 81.3% then your contact MIKE is correct, the idea of the 02 sensor is to analyse the exhaust gases and send a variable voltage reading back to the ECM depending on what it senses. I believe the voltage reads from  0.1volts up to a maximum of 1 volt, so as you can see that it doesn't take alot for that small a voltage to be incorrect. Maybe check all your earth, including the one connecting the engine to frame in front of the swingarm/rear fork.
3) Once fully hot , the 02 sensor value should switch quickly between its voltage values, indicating it is "probably" operating correctly.
4) Because the 02 sensor has being recieving an overly rich mixture the signal it sends back to the ECM is to reduce the pulse width of the injectors and there by reducing the fuel delivery making the intake mixture weaker, it will continue to do this until it senses a corrected exhaust gas value. This is why your plugs are still looking clean.
5)When installing the 02 sensor you made sure not to contaminate the sensor head, I believe the torque is something like 40ft/lbs to install.





                                                                                                                                                             

x1rider

Those are Metzeler tires (the mainly "road" ones for longevity).
A lot has happened since.  I bought a new Race ECM from Erik Buell Racing but that didn't work.  I looked at the calibration date and it was 1998, the Race ECM eeprom I tried flashing the stock ECM with was 1999 and both have the same issues (spitting through the intake between 2500-3500RPM, excessive leaning out, my plugs were white).
I contacted Mike Cobb and he sent me a 2000 Race ECM eeprom, I flashed my ECM yesterday, put new injectors, and a new O2 sensor in.  Hopefully if the weather is nice I'll be able to do a test run tonight or tomorrow.

jbee

Good luck x1 rider :up:
Just a thought, and one that doesn't have a quick and easy answer. Could it be an incompatability of parts, goodness knows the XB range suffer from some aftermarket exhaust systems that although well made just don't work well with them. with one particular exhaust by a well known German manufacturer I have seen set AFV values around 80% with a stock ECM and even with their own add on fueling device like a H-D race fueler made specifically for their exhaust on the XB's still give some extremely odd values and nearly always leaning toward the 80% mark.
Things to try an look at while you are test riding...
1) Does this spitting back happen in all gears at the specified rpm range?Spitting back is probably due to the ECM trying to lean the fuel because the 02 sensor is getting a rich exhaust reading.
This rpm zone maybe slap bang in the middle of where closed loop will work in certain gears.
Try disconnecting the 02 sensor, wouldn't recommend it for too long as the bike might go into limp mode/get you home mode, so carry a spare set of plugs and a spanner because it would probably richen the mixture or it may just throw a code.

2)Is it more related to sitting in this range either revving between2500-3500rpm slowly or at fixed throttle. Just 1st and second gear? Or is it still in the other gears but more subtle because you will be travelling faster?

3)Try to test ride at consistent temperatures and on the same roads through out testing. After each test plot your readings and feelings on a chart. After a few test does anything stick out?
4) If you get no luck, switch back to the standard exhaust tempararily, any difference/improvement or does it just move the problem?
5) Likewise with the airbox, if you still have it,lovely as it is :teeth: Any better?

6)Not related to testriding but a bit of an out of the box moment. If you could disconnect the 02 sensor wire at the ECM and provide the ECM with a consistent 0.5volts,not sure how!! Then it wouldn't be recieving the overrich voltage signals that is making the A/F value so low and possibly causing your spitting back. If you still have the old 02 sensor and don't mind damaging the sensor nose, you might find that a faulty sensor will sit at 50% voltage value and make no changes to the fueling. There again it may not work at all and send a fault code to the ECM. This is all presuming that the loop ystem is at fault.
7) Have sometimes found that the particular zone causing issues is the area that the bike is most often ridden in, if this is your case have you thought about changing the gearing, you might just move the issue into an area where it is less obvious, like a higher speed or if it is a loop issue out of the the way of the rpm zone you are having issues with into a none closed loop area where the 02 sensor can't affect the fueling.
8) Richening the A/F value in the affected area maywork or maybe changing the V.E. table might achieve the same thing.
Good luck
jbee
 
Does ECM spy allow you to adjust the A/F table?

x1rider

The ECM Spy allows adjusting both the fuel and timing maps, it's pretty versatile but I'm not qualified enough to start fooling around with those values.
I doubt it's the parts because the same combination worked well with the PowerCommander, I guess it's just a matter of finding a similar setting using the stock ECM.
I did ride with the O2 sensor disconnected and the bike runs better that way, a bit rich even (I like rich better than lean enough to make your spark plugs white as the driven snow).
The problematic range is between 2500-3500rpm, any gear, but under a constant load ie. cruising.  When accelerating through that range is works well, only spitting when the load becomes constant.

As soon as it's nice out, I'll try that new Race ECM flash, Mike says he's 99% sure it will fix the issue, I hope he's right.
Another thing, I sent a message to a guy who just bought a 2002 S3, Force exhaust (like me) and Forcewinder (like me) with the Race ECM and he has absolutely no issues.  He has a 1999 S3, similar setup, Race ECM that has the same issues as mine.  Something tells me that the Race ECM program may have changed between 1999 and 2000 (both race ECM calibrations I tried were older, 1998 and 1999).

...fingers crossed....