suddently no firing

[huub]

Went with both ecu's to the dealer, neither of them did work in his Guzzi's. Ordered me a new second hand one on ebay. Shall try it first in another bike, than stick it very carefully in mine...

[gstallons]

This ecu MAY have failed due to a bad input (tps,css,etc.) or output (ign.coil,etc..) device. Get and look at a wiring diagram and understand what is going on. I hope you understand how to use an ohmeter to test these circuits and devices.

This ecu might or might not have failed due to outside influences. You do not want to install another ecu and have it fail upon tuning the key on.

If you need help contact me and I will try to help.

[huub]

This ecu MAY have failed due to a bad input (tps,css,etc.) or output (ign.coil,etc..) device. Get and look at a wiring diagram and understand what is going on. I hope you understand how to use an ohmeter to test these circuits and devices.

This ecu might or might not have failed due to outside influences. You do not want to install another ecu and have it fail upon tuning the key on.

If you need help contact me and I will try to help.

 

I checked all the sensors in the circuit, they have all the right values. What can I check on the output?

[raz]

I checked all the sensors in the circuit, they have all the right values. What can I check on the output

You can think of the outputs as relay contacts with the other side grounded (but it's actually power transistors doing the equivalent job with microsecond precision). The coils and the injectors circuits look pretty much the same: they have a constant 12V on one side (fed by the power relay a.k.a the "injection relay"), the other side goes to the ECU. So when the ECU "activates" an injector, it just grounds that output at the right time and for the right duration.

 

In this environment, what could fry such an output is too much current. A shorted coil would blow its corresponding output transistor in the ECU. But probably nothing else would happen, the rest of the ECU would still function. The blown transistor will generally re-birth as a crowbar. It will conduct as a nail in both directions with or without power. If this has happened, it may fry the coil it was connected to (it's not designed to handle that continuos power). But hey, if we had a shorted coil in the first place that wont happen of course. The power fuse would blow instead. If we're really lucky it will actually blow before the transistor goes south.

 

For good measure you could check resistance in both coils and both injectors. It should be really low (couple of ohms off the top of my head) but not shorted. For example, to measure the RH ignition coil, disconnect the ECU and the power relay and measure between ECU pin 20 and power relay 87.

[Gregg]

I have just had a similar "no start" issue with my 2000 V11. It would sometimes after a long run refuse to start - this would then cure itself magically after about 5 minutes sometimes with the bike just sitting, sometimes with me quietly swearing at the bike or fiddling with relays and fuses.

This got worse about 3 weeks ago and I had to trailer it back home 50 miles to fiddle as nothing seemed to fix it. I thought I had isolated the problem to a bad injector relay which I then changed to a GEI one and the problem was gone for a couple of weeks.

The problem returned last week - I spent all day Saturday on it and found that the spade clips under the relay blocks were loose in the block and pushing back out of the block instead of engaging tightly on the male spade of the relay as the relay was pushed in - hard to pick as the blocks are tight up against the side of the tail body work. When I had fitted the new relay I must have just made enough contact to keep it running for a couple of rides till it vibrated away again.

I have now ordered a new set of the slide together relay blocks to fit up and see if I can fix the problem for good along with crimping the spring sides of the female connectors down well as I refit them - I just thought it was worth mentioning in case this is another culprit in your problem ?

Good Luck !!

[huub]

Yeah! Guzzi is running again! The second new ECU (second hand) is working! Motor is running fine. Thx all for your help!

[raz]

Thumbs up

 

Now to the question why the first one went bad while garaged... I guess we'll never know.

[mark.gilmore]

I have just had a similar "no start" issue with my 2000 V11. It would sometimes after a long run refuse to start - this would then cure itself magically after about 5 minutes sometimes with the bike just sitting, sometimes with me quietly swearing at the bike or fiddling with relays and fuses.

This got worse about 3 weeks ago and I had to trailer it back home 50 miles to fiddle as nothing seemed to fix it. I thought I had isolated the problem to a bad injector relay which I then changed to a GEI one and the problem was gone for a couple of weeks.

The problem returned last week - I spent all day Saturday on it and found that the spade clips under the relay blocks were loose in the block and pushing back out of the block instead of engaging tightly on the male spade of the relay as the relay was pushed in - hard to pick as the blocks are tight up against the side of the tail body work. When I had fitted the new relay I must have just made enough contact to keep it running for a couple of rides till it vibrated away again.

I have now ordered a new set of the slide together relay blocks to fit up and see if I can fix the problem for good along with crimping the spring sides of the female connectors down well as I refit them - I just thought it was worth mentioning in case this is another culprit in your problem ?

Good Luck !!

So your back on the road again Greg?Now you need to come for a ride up ths coast.

[huub]

I have just had a similar "no start" issue with my 2000 V11. It would sometimes after a long run refuse to start - this would then cure itself magically after about 5 minutes sometimes with the bike just sitting, sometimes with me quietly swearing at the bike or fiddling with relays and fuses.

This got worse about 3 weeks ago and I had to trailer it back home 50 miles to fiddle as nothing seemed to fix it. I thought I had isolated the problem to a bad injector relay which I then changed to a GEI one and the problem was gone for a couple of weeks.

The problem returned last week - I spent all day Saturday on it and found that the spade clips under the relay blocks were loose in the block and pushing back out of the block instead of engaging tightly on the male spade of the relay as the relay was pushed in - hard to pick as the blocks are tight up against the side of the tail body work. When I had fitted the new relay I must have just made enough contact to keep it running for a couple of rides till it vibrated away again.

I have now ordered a new set of the slide together relay blocks to fit up and see if I can fix the problem for good along with crimping the spring sides of the female connectors down well as I refit them - I just thought it was worth mentioning in case this is another culprit in your problem ?

Good Luck !!

 

I'm back on the road again. How's your v11-problem?

[Gregg]

I'm back on the road again. How's your v11-problem?

I am still waiting to get the relay blocks - patience is necessary with Guzzis in Australia. Glad to hear yours is up and going !

[mark.gilmore]

I'm back on the road again. How's your v11-problem?

Did I have one?Going to Thunder Rally next weekend,should see if you can come to catch up.