Hi Guys... Hopefully a straight forward one, but just posting this while I diagnose it on the bike. I tried to start the bike after a few months and the thing will turn over, has spark and will fire with easy-start spray then immediately stops, because no fuel is getting through. The fuses are all intact, so i guess it must be something to do with the injectors not getting power? The tank pump is running and there is fuel in the lines, just not getting to the cylinders. I have been modifying the bike, so changed the front wiring a bit, but can't see how that would affect it. Any thoughts?
I did actually fit CPC quick release connectors onto the hoses... Would be a likely cause? Not done anything in the tank though.
I think ST2 also has same set-up as most injection Ducatis with an internal hose that is prone to perishing almost like clockwork as the bikes get older. resultant pressure loss would affect starting/running. Have you run it since you fitted the quick-release junctions? I think you have to (carefully) physically check for fuel at injector(s) to begin with.
A couple of ( maybe ) obvious questions , but I'll ask anyway Does the fuel pump run for a few seconds then stop ? If it doesn't stop , the fuel is most likely running straight back into the tank , out of a tube that's split or undone . How long since the bike was last running well ? Have a look inside the tank filler , and turn on ignition ( some eye-protection might be good .... ) If you have a spare injector relay ( or one of the same type ) do the substitution thing , but to be honest , what are the chances that BOTH relays failed at the same time ? The engine should actually fire up on only one cylinder ( without Easy-Start ). Agree totally ..... I'm always suspicious of the last thing that was changed .
Thanks for your suggestions chaps... currently picking my way through these. There is no 'swirling' in the tank when the pump runs and ye, it does stop after a few seconds. I haven't been at the injectors yet, because the air box is a pig to remove. Going over my mods to the bike, I removed the digital display... this one: I don't like it, so i put an analogue temp gauge in instead. The LCD did display some fuel data when the ignition was on, so just wondered if removing it has confused the CPU? W
Re; quote from @oldtech :- "Does the fuel pump run for a few seconds then stop ? If it doesn't stop , the fuel is most likely running straight back into the tank , out of a tube that's split or undone" I can't say 100% due to failing memory, but on initially turning on ignition, I think the tank running for a brief period on some, if not all of our injected Ducatis is a "sham" prime and doesn't actually indicate that the fuel is now pressurised up to the Injectors and therefore "good to go".* Maybe it was intended to be used in this manner on conception which is more the norm on many cars and probably other brand motorbikes also, but got demoted due to some complication or for some reason. * i.e. - if fuel pump stops it doesn't mean that hose isn't split.
Re: "pig to remove"/checking for fuel up to injectors :- i've just popped out to my early Multistrada (ok, clearly not an ST2/not necessarily "lik-for-like") to confirm - if you can get your hand on a pressurised hose either going to, or returning from injectors, in much the same way as you might feel for an artery to check your pulse, I think you will find (I just did) that you can compress hose slightly but then on turning ignition on/pump run, you should instantly feel that it's become more solid and harder to compress with your thumb. You can repeatedly turn ignition on to try and confirm this, and hopefully, you'll also hear the pump energise at the same time to help confirm if you have fuel travelling or not.
Okay... Hoses didn't feel like they were being pressurised, so I removed the CPC connectors and ran a 'straight through' connectors, just in case they were the cause. There were a few drips of fuel from the hoses as I swapped them over. I would have expected a lot more. I then decided to keep the pipes disconnected and run the fuel pump. No fuel came out despite the noise of the thing running. there is still no signs of movement or 'swirling' in the tank. Could the pump be buggered, but still make the noise like it's running? Or, was Perry on to something with the fuel filter? If it was blocked, would that cause this issue? W
If you have to change the pump because it is fubared you’d change the filter in any case or I would. If you’ve no fuel pressuring the system then as you say the pump is blocked at the filter or pump broke. Can you undo just the filter side and see if that allows fuel at pressure to be pumped through? A filter is cheaper than a pump.
Somewhere i read a thread about o rings in the cpc connectors swelling and restricting/stopping fuel flow. When you take the cpc connectors out of the fuel pump so no fuel comes out so even when you run the pump no fuel should come out Put your old connectors back on.
Spent a bit of time today doing a diagnostic... I pulled the injector feed hose off the tank, filled a large syringe with petrol and forced fuel along the line to the injector bar. This I hoped would rule out an injector problem. If successful would also mean I could leave the air box on, which really is a pain to remove! I forced the fuel in while my daughter thumbed the starter and we got a splutter of life. That’ll do I thought. Clearly a pump / filter problem. Interesting thing is... I then reconnected the system and tried the starter again and the pump sounded different. Less high pitched and more gurglely (new word). Another stab and it burst into life. I may have just cleared something. Possibly an air lock or debris in the injectors, but she’s back up and running after a bit of faffing and thankfully no major expense. Fingers crossed!
