Hi Everyone, I've got a weird problem:

My engine cranks faster than normal, the fuel pump primes, but won't start.

It all started one cold morning, when after cranking for a maybe a minute it wouldn't start, and the battery went dead. I wrote this off to an old battery (which it was), bought a new one and installed it.

When attempting to start it with a new and charged battery, it cranked normal for a second and then started cranking much faster than normal. I think at this moment something broke but I can't figure out what it is.

I did think that perhaps the starter wasn't engaging the engine, but exhaust pops out of the tail pipe while I'm cranking so I'm sure the engine is turning.

The first suspect was the ignition system. I have NOT performed a spark test per say however I have verified that the spark plugs ignition coils are getting battery voltage on the Black/White wire which, according to the wiring diagram in the service manual, rules out fuses, the ignition switch, the kill switch, the bank angle sensor and the engine stop relay.

Also while I had the throttle body disassembled / visible and attempting to start, I did NOT notice any fuel coming out of the secondary injectors. But maybe the secondary injectors aren't active during starting? I don't know? I didn't smell any gas anywhere, but I DID hear the fuel pump prime.

I think it's has to either be the crank shaft position sensor or the fuel starter valve, but both of those would probably trigger a MIL light, which I do not believe I have when I turn the ignition switch on.

Any thoughts? I'd really appreciate any feedback.

 

Engine cranks faster?

Do a compression test. Faster cranking can be caused by low/no compression. Maybe the cam chain broke...

 

That's definitely a possibility. It really seems to me that no fuel is flowing though, no smell and no combustion type sound, but a broken cam chain would explain the fast cranking speed.

The compression is a good check point, I'll try that, thanks.

 

Yeah, but if a cam chain broke, you'd have valves open when the crank is spinning - and you'd be getting contact between the piston and valves that were open...

consequently doing a LOT of damage at the very least bending valves, right? Or do you think at that rpm, the piston could be pushing the valves back up and turning the cam?

I'd have to think you'd be able to hear that.

 

If it did break, you will absolutely have damage, and he did hear noises.
I hope that this is not the case, but under the circumstances a compression test is a good place to start. Ya hate to buy a bunch of sensors and take the bike apart a dozen times only to find that the motor is toast.

 

Oh, I missed that part where he heard those noises. Yeah, it would completely suck to dig through the bike only to find out that you have a ton of bent valves and what not. Tons of work and wasted money... I don't know if you could see it through the timing cover because of the crank position rotor, but you could definitely see it by taking clutch cover off

As far as the secondary injectors, while I don't know for sure what they do under start-up, I do know that they are hi velocity injectors (upper RPMs, WOT). It wouldn't surprise me that they don't activate at all under start up, but I'm not 100% sure.

 

...Or just do a compression test.

 

haha or that!