My 2002 998r is only running on the vertical cylinder, Ive established that the HT leads and coils are OK and so are the plugs. I’ve run the diagnostics using VDSTS and there are no error messages and all the tests ran fine. The belts are OK too. There is no spark when I earth the plug and turn the engine over and there does not appear to be fuel in the cylinder either as the plug remains dry even after I run the engine on one cylinder…..Im baffled! Any thoughts welcome.
you have your work cut out for you for sure. has bike stood for a while and have you seen any sign of light (usually green) corrosion when you unplug any loom connectors? it's worth going round all the ignition and injector related loom connectors for a start looking for corrosion. Key one that comes to mind is the large cylindrical multi plug on the right just behind rad (certainly on the more lowly 996's anyway) also there is a similar but smaller plug which is the main connector for the injector loom - you could also check for supply on both coils and wiggle/check all fuses before looking towards ECU despite checks. EDIT - just seen it's a multi plea thread Surveyor!
How did you test the coils? I found on my ST4s that the horizontal cylinder coil went a few years ago, and it manifested with occasional oruning on one from cold before it chimed in. Also at motorway speeds, if I flashed the hibeams with the dipped beams on, it would drop on one till I turned the lights off. Not good on a dark night! A new coil sorted it. A
I swapped the coils but the problem remained with the horizontal cylinder. I also ran the coil specific VDSTS diagnostics and it identified no problems with the coils. The consensus seems to be that it is an ECM problem. Im trying to locate one to try swapping it out so as to conclusiveley establish the cause of the problem.
