Yes, follow up to my previous post 1 very simple question: If I take the plugs out and crank the engine over by hand with the ignition on and the side stand up I should get sparks..yes? iF i DISCONNECT the fuel tubes and the fuel pump, should I still get sparks..or does the ECU monitor fuel pressure and prevent sparking if there's no fuel pressure or it's too low? I can hear the fuel pump relay clicking as I turn it over..but no sparks.
The ECU doesn't monitor fuel pressure. When the relay energises it power the injectors and the coils so you should get sparks, as long as the side stand is up, assuming the switch is ok, and the neutral light is on. It depends on the ECU getting a pulse from the crank sensor. Maybe turning by hand doesn't create a big enough pulse?
sorry, I've replied to this in various places. However, yes I have been grounding it/them and there is no problem with the side stand switch. So your point about not turning it fast enough to get a pulse maybe the answer here. So, thanks for that. I was trying to avoid cranking it with the starter....like to save it for when it's most needed!
How are you turning the engine? With a crank tool? Or with the back wheel and the engine in gear? Turning it with the back wheel preferably in 1st or 2nd gear will turn the engine faster and as long as the stand is up it should spark.
So I hand cranked it a lot faster and there were sparks on both cylinders. I put it all back together and it fired up fine but then started the same old thing, ie that it would stop running intermittently on one cylinder, namely the vertical cylinder. I established this by pulling the plugs and it would keep running on the horizontal cylinder. I think it's therefore fuelling since the problem started after I removed the tank and disconnected the fuel pipes (the tank has a very slow leak). Fuelling on the return cylinder. I've already removed the air box and taken the injectors out etc, but short of taking them to a specialist I cant establish if they are working properly. No evidence of any crud or debris in any of the filters. I replaced all the pipes in the fuel tank a couple of years ago and when you disconnect the pipes outside fuel does not continue to pour out (sign of a leak in the internal pipes..............?
Is it possible that even a slight loss of pressure in the tank would result in low pressure especially on the return feed? Maybe my pipes have perished slightly?
There should be no pressure in the tank. The pump supplies the injectors by the feed pipe and the pressure is set by the regulator in the tank on the return line, releasing excess fuel back into the tank. You can energise injectors using a 9V PP3 battery and squirt carb cleaner through them to clean them. You will find demos of that on YouTube.
