suddently no firing

[Guzzi2Go]

If there is no spark on both plugs I'd start with a phase sensor. You might need an oscilloskope though, and sensors datasheet.

 

Either try working your way up from the phase sensor via ECU to the ignition coils, or the other way around.

 

If it is phase sensor you should have neither sparks, nor should injectors work.

 

If it is ignition coil driver in the ECU, then injectors should work, but no spark(s).

[raz]

If it is phase sensor you should have neither sparks, nor should injectors work.

 

If it is ignition coil driver in the ECU, then injectors should work, but no spark(s).

In both cases the fuel pump would prime. That is why I suggest to forget about sparks and injectors for now and concentrate on the fuel pump. Find that problem and you'll probably solve all sympthoms.

[huub]

In both cases the fuel pump would prime. That is why I suggest to forget about sparks and injectors for now and concentrate on the fuel pump. Find that problem and you'll probably solve all sympthoms.

 

i'll concntrate on the fuelpump first... let you know if i find something.

[huub]

Some new conclusions:

 

-the fuses are ok;

-both the ecu-relais and the injection relais have 12 volt on connection nr. 30;

-the ecu-relais has also 12 volt on connection 87 if I turn the key;

-this connection is connected with connection 85 of the injection relais. Also there's 12 volt too.

-the other side of this relais (connection 86) is connected to the ecu (wire nr 19). The ecu should take care for ground on this connection? Thats not happening, on connection 86 is also 12 volt.

-so that's the reason that there's no voltage on connection 87 from the injection relais: the connection to the pump etc.

 

What should I do now?

[raz]

Yeah, checked the fuses. Before and after f2 there is 12 volt. There's also 12 volt on no. 30 and no. 87 of the relay. No. 87 is the connection to the pump, the injectors and to the coils.

When use a wire directly from no 87 to the pump, the pump is running but still no firing when I start. There's also 12 volt on no 86 of the relay (to / from the ecu), but not on no 85. That's the connection to the ecu relay and the ecu.

 

Now you tell a different story from the above

 

You should have voltage at 87 for 1-2 seconds after turning ignition on, then no voltage until cranking.

 

• If you have the 1-2 seconds of power but not when cranking, your camshaft position sensor is suspect.
  
• If you don't have even the 1-2 seconds of power, your ECU is suspect.
  

[dlaing]

-the other side of this relais (connection 86) is connected to the ecu (wire nr 19). The ecu should take care for ground on this connection? Thats not happening, on connection 86 is also 12 volt.

-so that's the reason that there's no voltage on connection 87 from the injection relais: the connection to the pump etc.

I am not sure about that.

When you are measuring 86 at the injector relay, I think you are measuring the voltage coming across from terminal 85, not the ground.

To measure the ground for terminal 86 you need to disconnect the injector relay and measure at the terminal 86 of the injector relay's connector.

Following what RAZ says when you turn the key on, you should observe the grounding of terminal 86 of the connector, but only for a second or two.

After a second or two, the grounding should go away.

 

Raz said,

* If you have the 1-2 seconds of power but not when cranking, your camshaft position sensor is suspect.

* If you don't have even the 1-2 seconds of power, your ECU is suspect.

[raz]

I am not sure about that.

When you are measuring 86 at the injector relay, I think you are measuring the voltage coming across from terminal 85, not the ground.

To measure the ground for terminal 86 you need to disconnect the injector relay and measure at the terminal 86 of the injector relay's connector.

I'm not sure what you mean this time, Dave. You are right in the details, but there is no need to disconnect the relay. If the voltage at 86 drops to zero you know it is grounded, by inference (is that the correct word?). You wouldn't want to try an ohm-meter or something, if that is what you meant, since we don't know exactly what's inside the blackbox pin 19 and you don't measure resistance on live parts anyway.

[dlaing]

I'm not sure what you mean this time, Dave. You are right in the details, but there is no need to disconnect the relay. If the voltage at 86 drops to zero you know it is grounded, by inference (is that the correct word?). You wouldn't want to try an ohm-meter or something, if that is what you meant, since we don't know exactly what's inside the blackbox pin 19 and you don't measure resistance on live parts anyway.

I am not sure what I mean either.

Sorry, I made a mistake.

When you turn the key on the 86 terminal should show zero or near zero volts and then after a second or two it should something like 12 volts, but maybe less because of coil resistance?????

And then one the engine is turning, it should show zero or near zero again.

And yeah, I see no reason to use an ohm meter, except maybe to test the relay when disconnected.

I was mistaken that Huub's conclusion here is wrong. I had the voltage backwards in my head.

the other side of this relais (connection 86) is connected to the ecu (wire nr 19). The ecu should take care for ground on this connection? Thats not happening, on connection 86 is also 12 volt.

-so that's the reason that there's no voltage on connection 87 from the injection relais: the connection to the pump etc.

But getting 12V at the 86 terminal is probably perfectly normal a few seconds after key is turned on, and the important thing is to get the measurements in the three scenarios: immediately after key is on, a few seconds after, and while cranking.

Of course there are other ways to diagnose this issue, but that is what I would do if fuses appeared to be good and swapping out the injector and ECU relays did not fix this issue.

[huub]

Now you tell a different story from the above

 

You should have voltage at 87 for 1-2 seconds after turning ignition on, then no voltage until cranking.

 

• If you have the 1-2 seconds of power but not when cranking, your camshaft position sensor is suspect.
  
• If you don't have even the 1-2 seconds of power, your ECU is suspect.
  

 

Sorry, I know. I'll drive you all nuts. But I was messed up and thought that another relais was the injection relais. Now I know better: the relais in the back is the injection relais and the one before that is de ecu-relais.

 

I don't have one second of power, so I suspect the ECU. This week I can stick the ECU in another v11, so then I know for sure.

[huub]

But getting 12V at the 86 terminal is probably perfectly normal a few seconds after key is turned on, and the important thing is to get the measurements in the three scenarios: immediately after key is on, a few seconds after, and while cranking.

Of course there are other ways to diagnose this issue, but that is what I would do if fuses appeared to be good and swapping out the injector and ECU relays did not fix this issue.

 

How can I measure that cranking-thing?

[Paul Minnaert]

well to measure if it has an open connetion, between pin 7 and 12 on the ecu connector, when ecu is out, you should have something like 680 ohms.

[dlaing]

How can I measure that cranking-thing?

Don't worry about testing when cranking.

If you are getting the same voltage immediately after key is on, and several seconds later, your problem is pretty darn likely the ECU or a connection.

[huub]

well to measure if it has an open connetion, between pin 7 and 12 on the ecu connector, when ecu is out, you should have something like 680 ohms.

 

You are everywhere! Thx.

[huub]

You are everywhere! Thx.

 

I measure 680 ohm!

[raz]

I told you so long ago

 

I hope your ECU is fine, it's the most expensive suspect