| Author | Message | ||
     T9r |
2003 XB9r 13,500 mi New plugs, new wires. This problem occured before the TPS was reset. Just used the VDSTS (techno research) to reset my TPS and the AFV (air fuel value) I was able to record it this time. Engine running, the Throttle Position set at 7.1% the Tach reading was 2730rpm then it dropped down to 2263rpm while the TP setting was steady at 7.1%. 467rpm drop The spark for the cylinder went from: Sf=spark front, Sr=spark rear Engine Temp went from 166 C to 168 C Sf=49, Sr=48 @ 2730 rpm Sf 38, Sr=37 @ 2265rpm Time period was about 5-10 seconds passed then returned back the the previous values. So the RPMs did a dip and I didn't move the throttle position. I got the problem to repeat itself. How do I trouble shoot it from here? (Message edited by t9r on May 18, 2006) (Message edited by t9r on May 18, 2006) | ||
| Davo |
Any trouble codes? What were the Engine Temps? Things to check: 1. Intake manofold leak. 2. Bad connections at the Battery. Observe BATT. voltage while you are hooked up to VDSTS. 3. O2 sensor and/or connections (Message edited by davo on May 18, 2006) | ||
| Davo |
The increased idle speed could be the 10 degrees of spark timing alone. The question is why is it advancing so far. ECM might be correcting a rich burn or it could be responding to a lean burn by advancing the timing to cool off the combustion chamber. I do not know the specific parameters of the spark timing in the ECM program. It is my guess that the problem is a minor external electrical or sensor issue. | ||
| T9r |
No trouble codes. Engine Temp was 166 - 168 degrees C. | ||
| Skully |
T9, Do you intentionally have the idle set that high? Keith | ||
| Davo |
168 C / 330 F is not even hot enough for the fan to run on when the key is turned off! The change in timing plus and minus 10 degrees could be the result of the ET (engine Temp sensor) Check the connections on the sensor. The O2 sensor and the ET sensor are near/on the rear cylinder and the wiring to them are less than bullet proof. The ET sensor will have a direct effect on the timing of the engine. There is a way to check the sensor. I will list the parameters of the ULY (xb12x)ET sensor. Volts Resistance Temp C 0.00/ 0/ 300 0.21/ 145/ 255 0.42/ 303/ 210 0.62/ 463/ 190 0.81/ 638/ 170 1.20/ 1042/ 150 1.59/ 1539/ 130 3.01/ 4991/ 85 4.43/ 25,647/ 40 4.63/ 41,295/ 25 4.83/ 93,759/ 10 4.88/ 134,200/ 0 4.93/ 232,414/ -10 Notice: An intermittent short would have very little effect at 168 C but an open or high resistance reading at the ET would make the timing change considerably. I would guess that it is a poor connection and not a short. Look for loose connector and/or corrosion in the connector. (Message edited by davo on May 18, 2006) (Message edited by davo on May 18, 2006) | ||
| Davo |
An intermittent short may have an effect after reconsideration. The remedy is the same......Check the wire and connections. | ||
| T9r |
Let me clear that up: At idle the bike TP is set 5.5%. I was holding the throttle open to 7.1% to get it to cause this problem. The problem is that the bike won't hold a constant (or semi constant) engine RPM, ie. the 500 rpm drop in engine speed. It happened when I held the throttle open at other percents too, not just around 7.1. Also the fan kicked on, when ignition was turned off, around 168 degrees C. (I'd have to check the manual for specs on that.) I'll check around the wiring, look at wear and connections. (Message edited by t9r on May 19, 2006) | ||
| Acidtuch10 |
Possibly intake seals? Mine had the same symptoms as yours and it turned out the front cylinder was sucking air .... Leaning it out and running hotter | ||
| T9r |
What might make the fan kick on sooner than listed in the manual? Would it also cause my symptoms? Manual says: Fan on @ Key on: 220 C(428F) Key off:170 C(338F) Fan off @ Key on: 180 C(356F) Key off:150 C(302F) Acidtuch10, How many miles on yours when you replaced the intake seals? Did you have any previous work that caused the intake to be removed? I'd had to replace them on an old S2 before, it was running really crappy though. | ||
| T9r |
Just wondering about this too... When the bike is at idle and I snap the throttle open, the engine revs up, but slowly returns back to idle. Slowly is relevant to the person I know but it just seemed not to be that fast to return to 1,000 rpm idle speed. In the case where it happened to the S2 it was an intake leak and and exhaust header leak. | ||
| T9r |
Problem was in deed a leaking front intake seal. Photos can be seen in this post: http://www.badweatherbikers.com/buell/messages/32777/207693.html?1150977116 |
