Hoping someone on here can help diagnose an infuriating intermittent stalling/restarting issue with my 2005 S2R 800.
It first raised its ugly head last week. Prior to that the bike had been pulling hard enough to wheelie under power in second, though it seemed a little sluggish and down on power.
Then the bike stalled at low speed soon after I left my house, and wouldn't restart. The starter cranked but it wouldn't fire, despite repeated attempts over a 30 minute period. I loaded it in my truck and drove it to my local dealer, where, of course, it fired first time. I asked the tech to look at it anyway as I didn't want to be stranded the next time it happens.
The tech said it had the wrong spark plugs (funny because the same shop put the plugs in last year), so he replaced those. Then he said it was only firing on one cylinder. So he checked the compression and the rear cylinder had none. Said one of the valves wasn't closing fully (had the valves done just 2,000 mile ago, again at the same shop, so I was surprised), so he adjusted that, charged me the better part of $600 and told me I was good to go.
It ran for a couple of hours and was definitely pulling harder with the correct plugs installed and the valve adjusted, according to my butt-dyno. Then the motor stalled again at slow speed and wouldn't restart. Again it cranked over on the starter but wouldn't fire despite repeated attempts. I left it alone for five minutes and then tried again and this time it started.
Any ideas what's going on?
Best advice I can give you, grab a spare plug go for a ride when it stalls pull a lead off each cylinder and check for spark on each cylinder in turn.
For now pull each plug and check the colour of each plug and see what you have. Check each coil as well. One might be on the way out and once the engine area get enough heat it might be enough to tip it over the edge. Check plug lead as well.
Be an idea to check each injector as well, could be a similar issue as I've explained with the coils.
When it wasn't starting, do you remember hearing the fuel pump run for a second after key-on?
I don't. But then I'm not sure what I should have been listening for? It certainly felt like it was starving for fuel when it stalled. My first thought was that I was out of gas, but I checked both times and that definitely wasn't it.
Forgive the newbie questions: Are you suggesting I replace the fuel pump? Or the relay?
Is there anything I can do to definitively diagnose if they're at fault while the bike is working?
Do you hear the pump whine when you turn the key on?
Replace the fuel pump on a guess? Nope.
You could either just buy the relay and plug it in when the bike stalls or make a jumper wire so you can jump terminals 87 and 30. Do keep in mind when you do this you have bypassed all starter safety features.
Thanks. I obviously don't want to cough up for a fuel pump if I don't need one. I'll try the relay.
Before swapping out stuff and wasting money. (which seems to be the norm)
Everything that has a coil:
ie injectors, coils, fuel pump and relay check the resistance when cold. Take the bike out and get it to stall, then check the resistance of everything again when hot.
Anything that is way out of spec once stalled and hot is more than likely to be the culprit. Coils can have a habit of passing ok when cold and not when hot. The fact that it will start after a while indicates to myself that the problem could be a heat related issue.
Checking the fuel filter lines can hurt either.
Diagnostics is not a process of swapping things out. It may fix the problem but not what is actually causing the problem. If you don't fix the cause you'll end up with the same problem down the line. The swap method can end up being expensive, ask any tech who does board level repair on electronic equipment.
Thanks. Good advice, I'm sure. I'm not convinced it's heat-related though because the first time it happened I'd travelled less than half a mile on a cool day and the motor was still coming up to temp.
There's a known issue with the fuel pump wiring on injected monsters, where the wiring breaks as it goes up into the tank. Maybe start the bike then see if you can make the fuel pump cut out by moving those wires around.
CA cycle works have a replacement wiring kit, so you don't have to buy the whole fuel pump assembly.
It was the pump itself, after all. The shop replaced it with a Bosch pump from a Toyota Camry, which was $175 as opposed to the $1k ducati part.
And being a German made part from a Japanese car, there's some chance of reliability to boot!
The next time it won't start ;with the key in off position put yur ear near the tank, put the key to ON and listen for whirr of fuel pump (it lasts only~3 seconds). If you have no sound then proceed with faulty fuel pump wiring diagnostics. there are many good threads on this.