V11 LeMans surging/missing when "hot"

[Guest scott]

First, want to say how impressed I am with this site!

 

My new LeMans has recently been suffering occasional surging/missing from idle to 3000rpm, and will occasionally stall out at idle. But (now for the interesting part), this only happens when the bike's engine is "hot".

 

This problem never existed until the outside air temperature rose above 90 degrees and the engine could really get heated up (like in stop-n-go traffic). Once this happens I notice decreased power at the lower rpm's, a lower and rougher idle (it normally idles at 1300rpm, but once "hot" idle seems to drop to 1000rpm), and engine surging/missing from idle to 3000rpm. It usually takes about 1/2 hour for this symptom to present itself, but again, only occurs if the engine gets heat soaked.

 

The only aftermarket item I've installed are LeoVince exhaust, and EFI is adjusted to 3.5% CO. The bike has over 3300 miles.

 

I've seen similar post, but has anyone found the actual cause? Thanks!!

[Guest Guest]

Scott, I had a similar problem with my V11 Sport, but it dissappeared (the problem, not the bike) after my 1K mile service was performed. I suspect that my problem originated with improper venting from gas tank and resultant vacuum, especially in hot weather. Does your bike's gas tank create a giant suction as the gas level drops? Or as the temperature drops? Mine did. Prior to the 1K service I mostly avoided the suction and poor performance problems by simply opening the tank or filling it up every 30 miles or so to relieve the vacuum. From speaking to other listers I got the impression that the vacuum was caused by a sticking "tip-over" valve in the gas tank, however Moto Italiano in San Mateo where I had the service performed said that the vent lines only needed to be re-routed. Regards, Joe in Modesto CA

[joe camarda]

Registered and logged on. Joe In Modesto CA

[joe camarda]

Scott, just realized that you are the "Newest Member" so welcome aboard! I just ordered a set of Leo Vince Ti-ovals today. Should take about 2 weeks to arrive Joe Camarda in Modesto CA

[dlaing]

1300rpm sounds a little high for an idle setting. If my tach is correct, you should idle smoothly at 1000rpm as my bike does. If the valves are too tight or your throttle bodies are out of synch, the idle at 1000rpm will not be smooth and may stall. But that would be regardless of heat. Also, I imagine that since your idle is 1300rpm, the gears must really clunk when you shift from neutral to first gear. If not than your 1300rpm idle may be fine. Cooler plugs would probably help, but that does not tell us why it is running poorly, and for all I know could result in burnt valves as the cooler plugs may allow the combustion chamber to work at a higher temperature. But I am no expert at plug swapping. good luck

[Guest hyper]

Scott, Did the gas tank venting mods work? My rosso had simalar problems when it was hot just after I brung it home from the dealer. When I phoned him he said it ran perfect but if I was unhappy they would try and fit it in over the next couple of weeks, (160 miles away). Thats what spending 18 grand gets you, the brush off. I rode it that way for a few days because it was good on the highway but sucked in town. Eventually I snapped and proceded to tinker. The first thing I noticed was that the air bypass screws located on the throttle bodies were completely closed. Also the tps screws had not been loosened by the dealer, in the guzzi liteture it says that they must be set up as part of the PDI procedure. In the Bible of guzzi books ( guzziology) it shows the whole procedure to set up our bikes. I would strongly suggest all guzzi riders get this book. I set up the synch, tps ,bypass screws etc. It transformed the bike into a sweet ride. Good luck and let us know the story. Thanks, Hyper

[Guest jimjib]

Does this book actually address the v11 sport in these areas?

[Guest hyper]

Jimjib, Yes,First Edition, Version5.1, phone the guzzi dealer in Seattle Washington , Hyper

[Frank]

Scott,

 

I can only tell you what my dealer did with my V11 LeMans. The bike was taken back to the dealer (Union Cycle in Indian Trail, NC) with a front engine cover oil leak and stalling when warmed up when coming to a stop. While there, I mentioned about the handlebar vibration and was asking about cures for this problem. When I picked up the bike about a week later, I noticed that the bike had much less vibration then when I took it in and hasn't stalled since. Also, there was now red paint drops on the TPS screws, indicating that the bike had been setup again since I first took delivery. I know that this dealership sets the CO at a level higher than the USA specs so that they will run better and this is done prior to delivery to the customer.

 

Here are the things that were adjusted to help the problem with stalling.

 

1. The valves were reset to Intake: .006 inch and the Exhaust to .008 inch. I believe I've heard this referred to as European settings.

 

2. The "tipover" valve was removed (I just found this out last night while I was adjusting the shock absorber - you have to remove the tank, battery and air box to get to the rear shock). This is a oneway valve attached to the right side rubber vent hose coming from the underside of the tank. This hose goes to the cannister located behind the exhaust crossover but in front of the rear wheel. The second hose, on the left, vents to atmosphere.

 

3. The TPS sensor was reset. Its easiest to do this with the "Diagnostic Tool" mentioned below and in MG's manual but it can be done with a voltmeter. See some URL's below.

 

If the CO needs to be reset, this has to be done using the Diagnostic Tool, really a software program with proper cable to plug into the bike's ECU. I bought this "tool" $500 by the way, and had fun with it but, although it can change the CO, you really don't know the actual tailpipe value unless you have a CO meter - a good one of these is over $1000. However, you can increase the CO with the "tool" and use seat of the pants and spark plug exams to get in the ballpark.

 

 

In my very limited experience with this particular model, you can tune the bike using only common metric hand tools, a volt meter and a vacuum gauge. The CO settings must be done with the Diagnostic Tool, which I believe all dealers will have. Below are some websites I've found helpful.

 

http://mphcycles.com/

 

They have two tech articles regarding throttle body setup for the V11

 

http://www.motointernational.com/main.htm

 

They can get you the most recent shop manual at a reasonable price - a copy of it really - since an original costs about $160. Their copies are much cheaper.

 

http://home.pacbell.net/guzzi007/sportissimo.html

 

Carl Allison's page regarding setup of the V1000 bike, the predecessor to the V11 sport and very similar. However, the V1000 idle enrichenment process can be done on the ECU, while our V11's need the software program.

 

http://www.technoresearch.com/

 

The company that makes the Diagnostic Tool for our Marelli (current 15M versions and earlier) - also has downloadable software updates on its site. They no longer sell the software directly but you must order it from:

http://www.klsupply.com/Performance/mdst/

 

 

There - probably more than you'll ever need.

 

Frank

[Guest jlburgess]

The dying at idle and low speed surging might be attributed to too tight valve lash. See the recent post on the valve adjustment per Raceco. My bike did the same thing until I added more free play.

[Guest scott]

Want to thank everyone for their help and suggestions regarding my LeMans. This is what I've done so far:

 

1) The valves were adjusted to the more liberal European settings (.006 and .008 inch).

 

2) The tip-over valve was removed (note: this was precautionary since my bike never exhibited a "sucking" sound from the gas tank).

 

These two items alone got rid of the stalling out at idle when very hot. I still have a surging/missing problem at about 2000-3000 rpm, but this only happens after the engine is heat soaked (like stop-n-go traffic in +90 degree heat). My dealer is working with the Guzzi tech's because it appears this is a far too common problem in areas where the outside temp gets well above 90-100 degrees.

 

I'll keep you posted, but it seems some temp gauge is overly leaning out the FI system. I don't see how the TPS could be involved if the bike runs great under all conditions except for extreme heat?

[Guest scott]

Oh, one more thing. My LeMans CO setting was adjusted to 3.5%. The dealer may bump that up to 4% but is waiting on more info from the Guzzi techs.