ok guys since doninigton I have not been able to start my bike! I have done a diagnostic which gives the following codes P0351 ignition coil a prim/secondary malfunction P0352 ignition coil b prim/secondary malfunction P0654 engine RPM output circuit malfunction Initially I thought crank position sensor which has just been replace and still won’t start? Any ideas? Could the immobiliser be at fault? Ecu? I am stumped!
Both the coils and the revcounter are driven from the ECU which derives these signals from the crank sensor but it has been replaced. An immobiliser issue will throw up various other fault codes and the LED in the revcounter will flash and then remain on. The amount of flashes indicates the particular immobiliser fault. If the coils are getting 12v, then the relay is ok and the fuel pump will be priming, the fault is most likely the ECU. You would be best to contacy @chrisw who should be able to help.
If you clear the codes that are stored (to make sure any old ones are removed and you're only looking at fresh ones) and then re-try, what codes reappear? So the bike was running when you got back from Donny, and now nothing? Start simple before going straight to ECU. I know that if my battery is even slightly down, my 4s will not start but will crank happily. What else have you checked?
I didn’t make it to donny it broke down on the way!! I have checked the relays for the fuel system, check the low tension side of the coils which seem ok I have drained the fuel tank to check the fuel lines etc I suppose I am trying everything other than ecu is there some pin test I can do to check if the coil side of the ecu is fecked!
If the fuel pump doesn't prime when you turn the key it could be the side stand safety relay, easy to link out to prove. But it sounds like yo are getting power and engine cranking?
Do you have the fuel pump priming when you turn the key on? Do you have any immobiliser light flashing/not flashing when you try to start? Have you pulled a plug and checked for a spark on both plugs? (Unplug the fuel pump when you do this to avoid potential removed eyebrows). You can test the injector outputs using JPDiag - you'll be able to see if you remove the air filter and open the throttle to see if the injectors fire or not - obviously without the engine running.
Yes the fuel pump primed and I can hear the relays click when attempting to start Immobiliser light goes out when the ignition is turned on and stays off when the ignition is off it flashed steady as it has always done! On a side note I did noticed the fuel likes in the tank seemed to be well worn and deformed like they had melted? So I have replace with some infuel style pipe I have but haven’t had chance to test that yet. Jpdiag seems to freeze a lot so haven’t had much look other than getting a diagnostic but will try the fuel injector test tonight
OK, interesting about your fuel lines. So if you can hear the relays energise when cranking, the ECU knows the engine is turning. As Johnny says, check all of the connections/earths (including the one to the ECU body) carefully, especially the coil low tension plugs - I have had the female terminals lose spring pressure (grip) on the coils, causing issues.
Ok I will pop the coils off tonight to so I can properly inspect the plugs and also do a full test of both sides The fuel lines did seem soft? I have a new fuel filter arriving today so I can finish that off and give that a try!
The fuel lines perish over time being immersed in fuel (exterior of hose not as fuel resistant as interior) This can cause issues at open throttle due to internal leaks starving fuel but shouldn't stop you starting and running at normal throttle opening. Fuel filter is worth changing if only to eliminate it - again shouldn't stop you starting
I had heard of the fuel line sucking closed with the draw of fuel however I didn’t know how it could affect this system
I'd put my money on it being electrical/ECU related to happen suddenly, as others have said check all earths and connectors/fuses etc. if your fuel pump has primed and you are getting the engine to turn it should easily fire even with substandard fuel lines/filter
that's why I mentioned it on here as I didn't know! on the mention of the side stand switch I have been able to start the bike with the side stand down just not in gear and the side stand down. could this also be a problem from the neutral light?
To be clear. If the bike is in gear the starter is inoperative as well as the ignition being cut, unless the clutch is pulled in. If a faulty neutral switch was the cause the neutral light would be out and the starter will only operate if the clutch lever is pulled to the bars. I don't think this fits the OP's problem.
Your ST4s may be slightly different to my ST4 but I thought they were the same, my wiring is such that the side stand being down prevents the bike from starting or running, there is a modification to change this to being in gear (as most Jap bikes are) so if yours has been modified that may be somewhere else to look? I would think it runs off the same relay so that would be the point to link out to eliminate as the cause
