Intermittent Single firing

[rockoil]

Hi All,

I am riding a 1999 996 biposto. I am not a hands on gurus but curious to know more about my bike and hopefully to understand it more.

My ride is suffering intermittent single firing. The horizontal cyclinder (nearer to the radiator) is giving me problem.

Symtons when the one cyclinder fail
* Bike feel suggish (need to throttle more)
* front exhaust header is not hot.

I also notice both my mufflers end do not have the same emission. Standing at the rear of the bike, the left mufflers (connected to the vertical cyclinder) is black and rich, the right mufflers (connected to the horizontal cyclinder) is clean and lean.

Send it to my mechnical and he suspect the injector should be the problem.
Just got a spare throttle body from Ebay and waiting for shippment.

Things i had done so far but problem still occurs,
1) Change spark plugs
2) Change spark plug cable

I hope anyone could advise my queries below
1) Will the cyclinder still work if running only with 1 injector? (i have 2 injector per cyclinder)

2) What is the damage to the bike if prolong of riding with only 1 cyclinder.

Will i start my bike now, i try to feel the front header to make sure it is hot.
However, when i feel the air emitted from the muffler, the right muffler feel hot, the right muffler feel room temp.

3) It this normal?

Any comment is welcome.

[ducati_750]

Pull the plug wires from each cylinder (one at a time) and hold the conductor next to the engine case while giving the starter a brief crank. If you see spark then your problem is likely a fueling issue.

If you don't see spark on either of the plug wires check the coils... it's also possible a lack of spark could be a problem with the ECU, but I'd start with the simple things....

[rockoil]

Originally Posted by ducati_750

Pull the plug wires from each cylinder (one at a time) and hold the conductor next to the engine case while giving the starter a brief crank. If you see spark then your problem is likely a fueling issue.

If you don't see spark on either of the plug wires check the coils... it's also possible a lack of spark could be a problem with the ECU, but I'd start with the simple things....

Hi,

tested the cable. spark is there.
Fueling should be the problem.

[ducati_750]

sounds like the problem is definitely something with the injectors, or the ECU controlling them. I don't know if it's possible, but you could try swapping the injectors to see if the problem shows up on the other cylinder? (be sure the wiring to the injectors stays the same, i.e. the wiring to the vertical cylinder injector stays at the vertical cylinder)... at least this would tell you if the injector were the culprit?

You asked if it's a bad idea to run the bike on one cylinder and I would say yes it is...I would run it only in very short duration in order to diagnose the problem

[rockoil]

Originally Posted by ducati_750

sounds like the problem is definitely something with the injectors, or the ECU controlling them. I don't know if it's possible, but you could try swapping the injectors to see if the problem shows up on the other cylinder? (be sure the wiring to the injectors stays the same, i.e. the wiring to the vertical cylinder injector stays at the vertical cylinder)... at least this would tell you if the injector were the culprit?

You asked if it's a bad idea to run the bike on one cylinder and I would say yes it is...I would run it only in very short duration in order to diagnose the problem

Hi,

I am waiting for my shippment of the spare throttle body i got from Ebay, after will do the swaping of the injector where i got more spare to play around.
However, the main problem is it is intermittent., as maybe i swap or even change the injector, i could not get the immediate answer.

What is the damage to the bike for running one cyclinder? The working cyclinder will be over stress and broke down earlier? I using my bike for street riding only.

I am worried as it may become single cyclinder when i am cruising on the highway constant at around 90kph where i think i may not able to feel it had become single firing already.