Breva 750 crank but no start

[Jurgen]

I need some ideas.  Put my 2004 Breva 750 away 2 weeks ago running until I turned off the ignition.  Ready to ride todayand it won't start.Turn on the ignition, the gages do their dance, the pump runs for 2 seconds, the starter cranks the engine but it won't start.  Tried several times and almost ran the battery down. 

The facts are: 1. Fuel pump runs and gages dance
                     2. Fuel tank 3/4 full and no swirl during pump running
                     3. Plugs dry (but nice and grey), no smell of gas, and no hint of a spark (yes, they were grounded)
                     4. All fuses are OK
                     5. Starter turns over the engine
                     6. I have not removed an injector, but suspect no fuel is being injected
                     7. I have not checked any sensors, don't know where they are.  Is the crank position sensor on the front of the    engine case directly in front of the left cylinder?
                     8. Any suggestions would be welcome.  (BTW, I know what makes an engine run, but havn't got a clue about an ECU and what inputs it needs to make it work). 

Jurgen

[oldbike54]

 Sounds like another case of fuel filter or hose separation . Open the gas cap , and watch for swirling .

 Dusty

[guzzisteve]

Yes, in front of LH cyl on top of case. Got a Workshop man? Here---

http://www.guzzitek.org/gb/ma_us_uk/750/Breva750IE_042003_Atel(GB).pdf

Check the relay's also the sidestand switch, clutch lever switch on LH lever perch on bars

Sidestand up & in neutral?

[sign216]

Are you sure there both no spark and no odor of fuel on the plugs?
That's odd.  Usually it's one or the other.

[Kiwi_Roy]

The pump primes when you turn the key ON
Does it re-start as the bike is cranking to indicate the ECU is getting pulses from the crank sensor?
It might be a little hard to hear the pump over the cranking but I suspect it should run for a second after

Sometimes it's hard to see a spark but if you grasp the plug in your hand and rest the same hand on the engine you will feel the spark as a tingle.
(don't ground any other part of your body)

[twowings]

It is worth your time to check the fuel filter...not a hard job and that way you will know for sure...

[Jurgen]

The pump primes when you turn the key ON
Does it re-start as the bike is cranking to indicate the ECU is getting pulses from the crank sensor?
It might be a little hard to hear the pump over the cranking but I suspect it should run for a second after

Sometimes it's hard to see a spark but if you grasp the plug in your hand and rest the same hand on the engine you will feel the spark as a tingle.
(don't ground any other part of your body)

Thanks Kiwi, After a few days of rest and putting the charger on the almost depleted battery, I put my ear to the tank while hitting the starter and sure enough, heard the pump run.  And about a second later, those nice exhaust notes of an awakening engine.  I think what the problem might have been was a low battery causing the ECU to shut down.  Therefore no spark or fuel.  That still doesn't explain why the fuel pump ran on turning the key since that signal also comes from the ECU (I think).  Anyway, I'm on the road again.  Jurgen

[timonbik]

"A good battery makes a happy Guzzi owner!!!"   Words to live by.

Cheers, Tim

[Kiwi_Roy]

Thanks Kiwi, After a few days of rest and putting the charger on the almost depleted battery, I put my ear to the tank while hitting the starter and sure enough, heard the pump run.  And about a second later, those nice exhaust notes of an awakening engine.  I think what the problem might have been was a low battery causing the ECU to shut down.  Therefore no spark or fuel.  That still doesn't explain why the fuel pump ran on turning the key since that signal also comes from the ECU (I think).  Anyway, I'm on the road again.  Jurgen

I think you might have hit the nail on the head, I have no idea at what Voltage level that happens, perhaps you could experiment over the winter.
The fuel pump would still have primed because at that point the starter was not sucking the battery down or perhaps the ECU doesn't care about the Voltage at that point.