Intermittent Firing on Single Cylinder

[Goodvibes]

Yesterday did my normal evening 50-mile run to clear the mind after work and parked for 10 minutes. Restarted but it was firing on a single cylinder with the service message/icon lit up. Checked for obvious plug disconnect and couldn’t find one. Rode away at half-speed so to speak for about 8 miles and the engine suddenly picked up on both cylinders. Rode OK for a couple of miles and it went back to 1 cylinder. Almost 3 miles from home went back to normal operation. Restarted in garage and everything was OK. Haven’t toggled through the diagnostic codes yet, but was curious if anyone has any obvious suspects to check. Thanks.

[Ghost_Bullet]

Check out this thread.. I am trying to find some images that I took of the problem.

[Ghost_Bullet]

The below pics show where things went wrong with mine, the pins for right side coil and stepper burnt off the ecu. I took to a place and they ran wires through the back of the plug and joined at the stumps of the pins in the ecu.

[GT-Rx]

Thanks for the photo post on this Ghost_Bullet!

[Ghost_Bullet]

Just found further records from the checks I made. (This all occured March 09)


Initial check
checked the diagnostic dash and found the following errors.

ECU 25 (error ignition coil 2 C.C. Gnd)
and what I have had for a few months now with no issue, ECU 60 (error stepper C.A.)
ECU plugs

Pin 9 - stepper + (broken off)
Pin 10 - right coil control (broken off)

Pin 18 - stepper -
Pin 19 - stepper -

Pin 26 - not used

Pin 37 right cylinder injector (appeared to be working)
Pin 38 left cylinder coil. (left coil had been working though)

The stepper motor was found to have fault last year in October(08), but not seen as critical at time to have repaired. If this previous failure has impacted on the now???

[Goodvibes]

Awesome information, I appreciate it very much! Checked the dash diagnostics module and there were no codes stored (either I don't know how to read the module, or the codes get removed once the problem goes away). Rode it some yesterday with no problems though, but my confidence in the machine is not where it once was. One's got to wonder what went on, and if indeed the ECU pins are shorting out. Will either take to dealer (under warranty) or get into the ECU myself.

[john zibell]

If under warranty I suggest taking it to the dealer. If it is a pin problem your action on them may give Guzzi a foundation to claim a maintenance induced failure. In other words, you messed it up.

Good luck

[Ghost_Bullet]

I would be sure to go in under warrenty if you can, as mine was outside of, and had the potential to cost thousands to replace ecu and loom as per shop recomendations.

I had the stepper error come up for a while before my full failure, and I had taken it to the shop, where they told me I may need to replace the stepper, but they obviously did not dig deep enough at that point, other than that the bike was running great.

[Goodvibes]

Well, had the Griso hauled to the closest Guzzi shop (the Guzzi roadside assistance worked very well) last Saturday to deal with the firing issue. I have concerns since the service tech asked if the handlebar shaking was part of the problem!! Hope to hear back from them this week with a diagnosis.

[Goodvibes]

Update: Cracked ignition lead to the spark plug was the problem. Diagnosed by spraying water around plug recess with engine running (technique recommended by MGUSA). Should have replacement lead in a week . Kudos to Broward Motorsports in West Palm Beach, Florida for really taking care of me and my Griso!