Lame Lambda?

[Eric]

2005 750 Breva. I've been having trouble with it since the Bush administration. I routinely checked things with VDST software and never got an error. Today the efi light came on and I rushed to the garage to hook it up. Clicked on the Engine button in the software and got a message "Engine Trouble!" This was the error. "lambda sensor: open circuit/short circuit to battery" Can anyone explain. I'm a little excited that this might the light at the end of the Breva tunnel.

[beetle]

Pull the plug on the O2 sensor. Measure across pins 3 & 4. Should be  ~12 - 15 ohms. If it's short or a lot higher value, the sensor is no good.

[Eric]

Pull the plug on the O2 sensor. Measure across pins 3 & 4. Should be  ~12 - 15 ohms. If it's short or a lot higher value, the sensor is no good.

Will give that a try. Might that explain the stumbling and periodic loss of power?

[beetle]

It might explain the stumbling. If the signal was wonky then the ECU would trim wonky. It would need to be still in spec but probably misreading the O2 however, as  the ECU would immediately throw up a SERVICE warning if either the lambda signal or heater current went out I spec.

It would not explain a periodic loss of power. You might want to pull the ECU connectors and check for cracks where water can get in, plus rust on the connector pins.

[Vasco DG]

Breva dash doesn't ave the 'Service' warning, just the EFI light but it's the same basic principle.

Ete

[Eric]

Breva dash doesn't ave the 'Service' warning, just the EFI light but it's the same basic principle.

Ete

Yes, and it seems to have a mind of it's own. You'd think it would come on and stay on if there was a problem but it comes and goes at will.

[Vasco DG]

The bike has had the map update and the phase sensor wire re-routed away from the coil?

Pete

[Eric]

The bike has had the map update and the phase sensor wire re-routed away from the coil?

Pete

No, Pete. I didn't know about those things. I started this quest to fix this stupid thing years ago and those issues were never mentioned. I kind of gave up a few years ago when we started spending all our time in the Ural. Lori liked the monkey thing. But she'd like to get back on two wheels and so we got the Guzzis out and the little Breva came back like a bad dream. Is there a thread or someplace that can fill me in on those mods?

[Vasco DG]

There was a tech bulletin on it years ago. As far as I know the map update is still available in PADS. The phase sensor wire is common sense, just move it away from the coil so it doesn't get pulsed by the field collapse.

Pete

[Eric]

There was a tech bulletin on it years ago. As far as I know the map update is still available in PADS. The phase sensor wire is common sense, just move it away from the coil so it doesn't get pulsed by the field collapse.

Pete

wow. Talk about being behind the times. I'm still using the VDST software I bought back in the day we got the Guzzis. For the Norge it's just been a toy. The Norge has always run well except for the stupid popping that I've gotten quite used to. PADS is a newer system, I suppose? Would a dealer be doing that kind of thing? We're a good 300 miles away from the nearest one. I wonder if the computer can be flashed without having it on the bike. I'm headed down that way for a Ural rally in a few days so maybe I can just take the computer down. I'll try and find the phase sensor wire and check that out.

[M0T0Geezer]

You can turn your Breva 750 into a sweet loving thing.  Send the ECU to Todd over @ GuzziTech and pay him whatever he wants to reflash it.

That is what I did with my '04 Breva 750 at 10,000 miles.

I had bought it used in March 2013 with 6500 miles.  The Previous Owner had equipped it with a Power Commander, O2 Optimizer, and Mistral exhaust.  Hard starting, bucking, surging, backfiring bitch she was, and barely getting 40 mpg.  For 3500 agonizing miles I tried to get that little bike to run right - but failed.

In desperation I sent the ECU to Todd and he had it back to me in a week.  No more Power Commander, no more O2 Optimizer needed (sold them on eBay).  The existing O2 (lambda) sensor stays in place and connected, but the ECU no longer pays any attention to it ("closed loop" mode).

Now, at 34,000 miles, my little Breva is my favorite motorcycle of all time, and I've had a few.  It has perfect manners (eager starting, no bucking or surging), the popping is completely gone, and I regularly get high 50s in gas mileage.  Win win win.

'Geezer

[pauldaytona]

Eric, you can put the latest map on yourself, look for the topic about Guzzidiag. If you buy the two cables (30$), software comes free.  Can do anything with norge and breva. Not only the things vdst can but mapping(flashing) too. The breva should be a good running bike in stock shape, no expensive things needed. 
I can mail you the map.

[Eric]

Worth a try. Where do I get the cables?

Eric, you can put the latest map on yourself, look for the topic about Guzzidiag. If you buy the two cables (30$), software comes free.  Can do anything with norge and breva. Not only the things vdst can but mapping(flashing) too. The breva should be a good running bike in stock shape, no expensive things needed. 
I can mail you the map.

[Vasco DG]

wow. Talk about being behind the times. I'm still using the VDST software I bought back in the day we got the Guzzis. For the Norge it's just been a toy. The Norge has always run well except for the stupid popping that I've gotten quite used to. PADS is a newer system, I suppose? Would a dealer be doing that kind of thing? We're a good 300 miles away from the nearest one. I wonder if the computer can be flashed without having it on the bike. I'm headed down that way for a Ural rally in a few days so maybe I can just take the computer down. I'll try and find the phase sensor wire and check that out.

PADS is the current factory tool. Hadn't thought about the fact Paul would probably have the updated map stored and available through 'Writer'. Duh!

VDSTS is long outdated and was always a fairly ordinary tool.

Pete

[beetle]

Worth a try. Where do I get the cables?

Amazon or ebay or HERE

OBD2 usb cable with FTDI electronics. Fiat 16 to 3 pin adapter.