Toystoretom
Living Legend
- Joined
- Feb 25, 2006
- Messages
- 2,449
Not all Rockets are exhibiting the same symptoms when a poor idle situation starts to happen. Many bikes start to have the idle degrade as the bike's engine becomes warmer, and this seems to be aggrivated by warm weather. For this situation I would recommend trying the first fix....
However... some Rockets won't even run correctly when cold and first started. The bike will barely start and it will act like it is only running on one or two cylinders and it almost seems like the throttle isn't connected to the throttle bodies, if you twist the throttle not much happens. As the bike warms up it begins to run a little better but it still runs poorly. This fix may help this situation.
Here is the theory behind this fix. The Rocket has an ECM that gets readings from many different sensors on the bike and it uses this information to run the fuel injection and ignition. If you look at the factory service manual on page 11.16 you can find a list of these sensors, and if you look on page 11.133 you will find a description of the Engine Management Adaptation process. The ECM constantly reviews the readings from these sensors and makes adjustments to make the bike run better. You can reset this system by doing the 12 minute tune. If you do the 12 minute tune and it doesn't help or you can't do the 12 minute tune (the bike won't run long enough, stalls, or loads up and dies) something is wrong....
What we have found in some cases is the ECM is "seeing" the wrong values for a sensor, in fact the voltages are so out of range that the ECM becomes confused and it no longer works correctly, and the bike goes into a failsafe situation or will just barely run as described above. Usually it isn't a faulty sensor.
Most sensors on the bike are fed a 5 volt reference voltage. The sensor will change this voltage and send it back to the ECM, and this new voltage is what the ECM "sees". The ECM then can tell what that sensor is experiencing and makes decisions based on that. It expects to see voltages that will be in line with what other sensors are seeing, if it doesn't it may decide something is wrong and throw a check engine light or go into failsafe. This ECM has a nasty habit of just failing to operate correctly when this happens.
Many of the incorrect readings the ECM "sees" are caused by the bike's wiring harness. Many of the connections in the plugs (or connectors) start to loose their ability to transfer electricity without resistance due to poor manufacture, coorosion, dirt or moisture. The more resistance the less voltage will pass through that connector and the ECM will see an inacurate reading. Sometimes pins in the connectors will loose contact alltogether and an open circuit will result. This is a very common problem on fuel injected cars, and causes the vast majority of runnability problems with them.
The Fix...
Once again I am trying to do things that most people can do at home..
Disconnect BOTH battery cables. You will be working with electrical connectors and some of the wires are hot at all times. We don't want to fry a component or blow any fuses... we are trying to fix it, not burn it down.
Lift the gas tank and put it on the prop wand. Please refer to your shop manual, 2005 is different than 2006...
Remove the seat and the right side cover...
Take a look under the gas tank, you will see many electrical connectors under there. There is one large grey one in particular that is actually the engine sub harness, my bike has the Power Commander adaptors plugged into it...
What I want you to do is, one at a time, disconnect these plugs and inspect the male pins. Older bikes do not have dielectric grease in them and the newer ones do. Sometimes this grease is somewhat excessive, you can wipe it away with a soft rag. Inspect the male pins for damage, coorosion, and water. You can use some electrical contact cleaner on these pins (available at any auto parts store) if you find water or coorosion. Take a small screw driver or a pair of small needle nose pliers and just barely tweak the male pins. By just barely moving them we hope to make a better connecton when we plug the connectors back together. Be careful... if you tweak them too much the plugs won't snap back together. If this happens don't force it, inspect the male pins and see which one(s) are too far tweaked to allow the two halves of the plug to reconnect and straighten those pins out.. Put some fresh dielectric grease on them (Also available at any auto parts store).
Another couple of connectors to check are the two that snap into the ECM....
Just gently unplug these and then reconnect them, and then wiggle them. This is a sensitive device and that should clean up the connectors (I hope)...
Many sensors have a "Pigtail" or a small subharness that plugs into the bike's main harness. This is the one for the Primary Throttle Positon Potentiometer. Clean these connectors also...
Use the shop manual to locate these... there are connectors for the coolant temp sensor, the crank angle sensor, the gear postion sensor, the intake air temp sensor and so on.
After you clean and modify a plug mark it with a paint pencil so you know its already been done.
Put the bike back together... reconnect the battery cables and start it. You may have to play with the throttle to get it to run at first but hopefully it will run better after a bit. If it does... let the engine cool off completely and then do the 12 minute tune.
Tomo
However... some Rockets won't even run correctly when cold and first started. The bike will barely start and it will act like it is only running on one or two cylinders and it almost seems like the throttle isn't connected to the throttle bodies, if you twist the throttle not much happens. As the bike warms up it begins to run a little better but it still runs poorly. This fix may help this situation.
Here is the theory behind this fix. The Rocket has an ECM that gets readings from many different sensors on the bike and it uses this information to run the fuel injection and ignition. If you look at the factory service manual on page 11.16 you can find a list of these sensors, and if you look on page 11.133 you will find a description of the Engine Management Adaptation process. The ECM constantly reviews the readings from these sensors and makes adjustments to make the bike run better. You can reset this system by doing the 12 minute tune. If you do the 12 minute tune and it doesn't help or you can't do the 12 minute tune (the bike won't run long enough, stalls, or loads up and dies) something is wrong....
What we have found in some cases is the ECM is "seeing" the wrong values for a sensor, in fact the voltages are so out of range that the ECM becomes confused and it no longer works correctly, and the bike goes into a failsafe situation or will just barely run as described above. Usually it isn't a faulty sensor.
Most sensors on the bike are fed a 5 volt reference voltage. The sensor will change this voltage and send it back to the ECM, and this new voltage is what the ECM "sees". The ECM then can tell what that sensor is experiencing and makes decisions based on that. It expects to see voltages that will be in line with what other sensors are seeing, if it doesn't it may decide something is wrong and throw a check engine light or go into failsafe. This ECM has a nasty habit of just failing to operate correctly when this happens.
Many of the incorrect readings the ECM "sees" are caused by the bike's wiring harness. Many of the connections in the plugs (or connectors) start to loose their ability to transfer electricity without resistance due to poor manufacture, coorosion, dirt or moisture. The more resistance the less voltage will pass through that connector and the ECM will see an inacurate reading. Sometimes pins in the connectors will loose contact alltogether and an open circuit will result. This is a very common problem on fuel injected cars, and causes the vast majority of runnability problems with them.
The Fix...
Once again I am trying to do things that most people can do at home..
Disconnect BOTH battery cables. You will be working with electrical connectors and some of the wires are hot at all times. We don't want to fry a component or blow any fuses... we are trying to fix it, not burn it down.
Lift the gas tank and put it on the prop wand. Please refer to your shop manual, 2005 is different than 2006...
Remove the seat and the right side cover...
Take a look under the gas tank, you will see many electrical connectors under there. There is one large grey one in particular that is actually the engine sub harness, my bike has the Power Commander adaptors plugged into it...
What I want you to do is, one at a time, disconnect these plugs and inspect the male pins. Older bikes do not have dielectric grease in them and the newer ones do. Sometimes this grease is somewhat excessive, you can wipe it away with a soft rag. Inspect the male pins for damage, coorosion, and water. You can use some electrical contact cleaner on these pins (available at any auto parts store) if you find water or coorosion. Take a small screw driver or a pair of small needle nose pliers and just barely tweak the male pins. By just barely moving them we hope to make a better connecton when we plug the connectors back together. Be careful... if you tweak them too much the plugs won't snap back together. If this happens don't force it, inspect the male pins and see which one(s) are too far tweaked to allow the two halves of the plug to reconnect and straighten those pins out.. Put some fresh dielectric grease on them (Also available at any auto parts store).
Another couple of connectors to check are the two that snap into the ECM....
Just gently unplug these and then reconnect them, and then wiggle them. This is a sensitive device and that should clean up the connectors (I hope)...
Many sensors have a "Pigtail" or a small subharness that plugs into the bike's main harness. This is the one for the Primary Throttle Positon Potentiometer. Clean these connectors also...
Use the shop manual to locate these... there are connectors for the coolant temp sensor, the crank angle sensor, the gear postion sensor, the intake air temp sensor and so on.
After you clean and modify a plug mark it with a paint pencil so you know its already been done.
Put the bike back together... reconnect the battery cables and start it. You may have to play with the throttle to get it to run at first but hopefully it will run better after a bit. If it does... let the engine cool off completely and then do the 12 minute tune.
Tomo
Last edited by a moderator:
Thanks for posting pics. They really help.
