Low idle. K-9, injector

The fun did not last long. Took the bike for a ride. The check engine came on again. The ride is rough, though, I can't say there is any lack of power. There are lags when turning the throttle slightly, then when I give it more spin it starts running well. There was extra oil, that I sucked out, checked all the sensors again, seem to be all good. The spark plugs were black though, not with oil, the way they usually get black when there is too much gasoline and not enough air. I am thinking of changing the spark plugs now. Will order a pair of these e3-36plugs. So it is not the ICV.
 

Jersey Big Mike

100K mile club
The fun did not last long. Took the bike for a ride. The check engine came on again. The ride is rough, though, I can't say there is any lack of power. There are lags when turning the throttle slightly, then when I give it more spin it starts running well. There was extra oil, that I sucked out, checked all the sensors again, seem to be all good. The spark plugs were black though, not with oil, the way they usually get black when there is too much gasoline and not enough air. I am thinking of changing the spark plugs now. Will order a pair of these e3-36plugs. So it is not the ICV.
reset the maps in the VFI would be the first thing I would do if you haven't already.
Power on, run, power off for 20 secs and power on again.
Ride for 10-15miles at least and it should rebuild the map.
Do this when you put the new plugs in. O'Reilly usually has te E3 plugs (find in the small engine/lawnmower section).
 
Today changed the spark plugs. Installed NGK as they were the only currently available here in the UAE. It will take around 2-3 weeks to get E3s. Below are the pictures of the old ones. Tried to reset the maps manually several times, but did not work out. Connected to Pro Tune. It showed Throttle position low issue. Played with the sensor, spinning it different directions until I got a green message. Then chose the advanced mode and reset the adaptive maps in Pro Tune. The bike seems to be working fine, at least the idling. Will take it for a test ride later when the heat goes down.
 

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Finally, the bike is riding great! Half an hour, no issues. The idle is stable, no misfire. What was done: throttle body cleaned, air filter cleaned, all the sensors cleaned and the ICV replaced, oil level fixed, spark plugs changed, maps reset to zero.
 
Back to "normal")
Went to pick up my daughter from school today. Everything was fine, the bike was working great. Parked it for 5 min to meet the daughter. Started the bike, no problem. As soon as I moved the bike lost power. It seems like the rear cylinder switched off/no spark. Managed to get home on the front cylinder, the rear would switch on a couple of times. I had this issue before. I changed the coil and the wires then. The wires are screaming eagle. Any idea what this might be?
 

Jersey Big Mike

100K mile club
Back to "normal")
Went to pick up my daughter from school today. Everything was fine, the bike was working great. Parked it for 5 min to meet the daughter. Started the bike, no problem. As soon as I moved the bike lost power. It seems like the rear cylinder switched off/no spark. Managed to get home on the front cylinder, the rear would switch on a couple of times. I had this issue before. I changed the coil and the wires then. The wires are screaming eagle. Any idea what this might be?
Make sure the rear plug is snug (always check last changed item)
check for rear plug
Check for spark at rear plug

I had this happen once on one of my other bikes with iridium plugs because the tip broke/burnt off and I lost an effective spark.
 
This happened before with NGK spark plugs. Rear cylinder switched off after some time. I will change them back to champions again. I understand the rear cylinder switches off by ECU when it gets the signal that the engine overheats. It is +48C over here now. However, it did not happen until I stopped and switched the bike off. Can there be a faulty signal? I am about to start digging further if spark plugs replacement doesn't help. Will check the ignition module. Also, BDM EHC looks a bit complicated. There is a special software to test it from what I got in the manual. Can it be replaced with a more common unit, from a Harley?
 
A new update.
For those who have VFI engines. V124 in my case and have O2 sensor issues.Big Dog is selling them for $395 + shipment ($50).Not sure if they some anniversary edition, they should be for this price. Even the brand is unknown, should be Bosch, but don't look like they are from Bosch. So, I ordered original Bosch sensors. They come in a compressed package with some grease on the thread. The connectors are different though. However, 2 sensors cost me $ 140 with a shipment and I bought to email connectors $ 7 each. Plus, when I was checking the "original" Big Dog connectors, I realized that it is just a pig tail connected to the main harness and one of the wires had about 2 cm of another white wire attached to it. Guys from Big Dog, if you are reading this, my only question is WTF? I think if I get drunk, swallow mushrooms and not sleep for three days my quality of work will be much higher.
 

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Jwooky

Well-Known Member
Great you found the sensors from Bosch. Might want to post a link of where you found them.

I suspect someone has hacked up your harness. No way they would do that in a OEM harness.
 
Great you found the sensors from Bosch. Might want to post a link of where you found them.

I suspect someone has hacked up your harness. No way they would do that in a OEM harness.
Here is e-bay link:

I contacted bosch directly and they gave me the number of a local (Dubai) dealer.
As for the harness, I can't prove as I bought this bike from one owner, who only rode it a couple of times. I just see how badly the tank was lined inside and the amount of parts I have already changed on this bike, which had only 5,000 miles when I bought it. The bike is nice and beautiful but unreliable, and it is always some electric issue. It is like a BMW or Range Rover, every second day you will be fixing it. I saw one K-9 on the weekend, the owner got tired of all the eternal issues and installed the whole power train from Sportster 1200))). Now he is happy.
 

HMAN

I just like my Freedom
Here is e-bay link:

I contacted bosch directly and they gave me the number of a local (Dubai) dealer.
As for the harness, I can't prove as I bought this bike from one owner, who only rode it a couple of times. I just see how badly the tank was lined inside and the amount of parts I have already changed on this bike, which had only 5,000 miles when I bought it. The bike is nice and beautiful but unreliable, and it is always some electric issue. It is like a BMW or Range Rover, every second day you will be fixing it. I saw one K-9 on the weekend, the owner got tired of all the eternal issues and installed the whole power train from Sportster 1200))). Now he is happy.
Its always a love/hate relationship with these Dogs. When they are right, ya cant wipe the smile off ur face, when they down....find me some C4! Hang in there. It'll come together. Remember always....cool aint cheap.
 
Now the next thing is a crankshaft position sensor)). I am very positive it is dying. The bike starts fine, ride it till it reaches 250F. Then stop, turn the engine off, wait for 5 min or so and start. Rear cylinder is missing. Start moving on the front one and in a minute the rear switches on again. I read it is most probably this sensor. I did not like the way it is connected. It goes all the way up to where the VFI is. Now, just to replace it I have to cut all the clamps that hold the wires to the frame and remove the fiber glass cover. Has anyone tried to install Harley crankshaft position sensor instead? They look identical. The wire is short and the connector is different, which is not a problem.
 

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Jwooky

Well-Known Member
The sensors are the same with Harleys, just different connectors like the O2’s.

However, there is only one common sensor, not front/rear.
It’s not sensible that it could be the cause of front not firing.

The coil is the only front/rear unique part that comes to mind
 
The coil is new. I had the same issue with the previous one, so I changed it. I understand that the crank position sensor is sending a signal to the VFI of which cylinder to fire. The rear cylinder fails to fire after a stop, then it comes back to normal. No check engine is on though. Here is a video:
The guy had similar symptoms.
 
Finally, the bike is back to life (hope the joy will last for a long time now).
Now, about the issue.
The eternal problem with the rear cylinder not switching on after riding and stoping and starting the engine. It would switch on after about a minute though. Nothing helped: almost every sensor had been changed. S&S suggested to change the whole VFI module. That was going to be the last step before changing the crank position sensor. While waiting for it from Big Dog I opened the battery tray again to check the wire connection... And here it is, laying on the bottom of the frame, covered in dust, was the cause of all evil, the relay. It simply fell off some day, causing all the trouble. I am not able to upload a video, but it was shaking badly in its connection. The only solution so far was to fix it with a cable tie. In future I am planning to change the wiring and, maybe, downgrading it to a carb to get rid of the mess. To sum up, if anyone is thinking of buying a VFI Big Dog, go, do something nice, have fun, enjoy life and get this shit out of your head. To Big Dog guys: fire you electricians. I don't know which influence they are under when assembling your bikes: booze, drugs, mushrooms or any other shit, but unless you do something about the electrical part, no one is gonna buy your new bikes, at least not overseas.
 

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Just FYI, that is not OEM wiring, or relay. Some hacked on that bike.
I wish that was the case. The relay seems to be in the place it was meant to be from the factory as it is connected to the battery tray the way it should be. It is just the wiring, the length of the harness, which does not match the size of the bike, the quality of the tank paint from inside etc.
 
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