sputter-sput when hot

[Ronkom]

2000 V-11 Sport, only 14K miles. I went-over this bike, new battery, rear brake pads, fluids change,  detailed etc. Ran great. Sold to a friend a few weeks ago, he's been a very happy camper 'till today (Friday 13!). This is the first really warm day we've had, (touched 80 degrees). I get the call, bike backfire-sputter-sput quit & won't start. After several hours cool down, fired right up ran fine....for about 10 miles. Sputter-sput routine again. After an hour cool down it made about 2 miles before it quit again. So, wisdom of the forum, what's getting hot & causing the problem??
Thanks,
Ronkom

[pete roper]

Phase sensor.

[LowRyter]

You might check if the TPS plug isn't loose.

[fotoguzzi]

Phase sensor.

what he said.. the wire coming out of the cam sensor gets real hot and has a sharp bend so, shorts?

you did set the valves right?

[guzzisteve]

Basics--- Fuel, Spark, Air        If it ran fine cold, have him ride over & check the spark, it'll be warm a couple more days.

By going over it I take it you changed air filter set up TPS and balanced TB's.

[rodekyll]

You might also want to check that the engine temps sensor is seated and not lying on the engine somewhere.  Mine did that when the plastic holder broke.

If external pump, then hose routed for vapor lock?

[Sasquatch Jim]

It's broke, send it to me and I will dispose of it for you.  No charge.

[spreadeagle]

TANK PRESSURE?

[i HONK]

I had a similar problem on my 02 V11 LeMans. Fuel pump was vapor locking and it would not start when hot. I insulated the pump and made a air inlet manifold to supply fresh air from the front of the frame,  Problem solved
Randy

[Vagrant]

Once again no I'd where u live but winter gas doesn't work on not days

[Scott DeRoss]

Basics--- Fuel, Spark, Air        If it ran fine cold, have him ride over & check the spark, it'll be warm a couple more days.

By going over it I take it you changed air filter set up TPS and balanced TB's.

Coils?

[Chuck in Indiana]

Coils?

Both at once? Probably not, although one would do that.

The vapor lock is a known issue, solved by an insulated fuel line. I would imagine it's been done to an 02.
I'm betting on the phase sensor..

[bigbikerrick]

Hi Ron, my Rosso Mandello did the same thing, vapor lock with fuel boiling in the fuel line/pump/filter. I could get a water bottle, and squirt cool water at the offending parts,and it would fire right up. It left me temporarily stranded at gas stops until i figured it out. I eventually insulated all the fuel line components with fiberglass "header wrap" and aluminum foil on the outside, all held together with zip ties....problem solved. Man, I sure miss that bike ! It was my first Guzzi.
You never forget your first Guzzi...be it good or bad memories.
Rick.

[Chuck in Indiana]

If vapor lock *is* the problem, firesleeve will cure it.
https://www.aircraftspruce.com/search/search.php?s=silicone%20firesleeve

[Ronkom]

OK, Fuel filter changed, TPS checked, TBs balanced, temp sensor solidly in place (I assume that it's screwed into the right jug..on the inside). I will recheck the valve settings. The phase sensor is a right expensive bit to trial&error, any way to test it?
Not looking forward to wrestling the tank off & back on again....it's been "ethanoled" a little swollen.
Ron

[Chuck in Indiana]

OK, Fuel filter changed, TPS checked, TBs balanced, temp sensor solidly in place (I assume that it's screwed into the right jug..on the inside). I will recheck the valve settings. The phase sensor is a right expensive bit to trial&error, any way to test it?
Not looking forward to wrestling the tank off & back on again....it's been "ethanoled" a little swollen.
Ron

Absolutely. Unplug it and check it. I think.. 680 ohms. You can also check it at the plug to the computer. I'll get back to you on which..
Here ya go, Ron.. Pin 7 to pin 12 at the ecu connector. No need to pull that swollen tank.
2018-03-25_04-07-12 by Charles Stottlemyer, on Flickr

[Ronkom]

OK Pulled the plug from the ECU (Factory plug, bypassing the installed Power Commander). Hooked up leads 7&12  to my Fluke meter, hit the wires, top of the Phase Sensor, & block around where the PS is bolted in w/a heat gun. Ambient temp reading of 686 ohms quickly started climbing. At 714 & killed the heat (wires were fairly warm to the touch). Pulled the PS from the block (it was clean, no metal filings etc.)  & hit it directly w/the heat gun, reading climbed VERY quickly.... at 788 ohms I stopped. Sensor body was "cuppa coffee" hot to the touch. What say....replace it?
After typing this, PS is back at ambient (to the touch) meter still reading 704 ohms.
Ronkom
 .

[Chuck in Indiana]

I'm no electrician, Ron.. but it sounds ok to me. Maybe Kiwi Roy will chime in.

[guzzisteve]

I would just ride it w/timing lite on it, when it cuts out you pull the trigger. It either lites up or not.

[LowRyter]

It doesn't sound like it's been determined that either cylinder isn't firing, rather than a misfire for both.  It's pretty easy to diagnose it when you ride because the dead cylinder is much cooler to the touch.  If they feel the same, then the misfire affects both sides.

I had an intermittent problem with my EV due to fuses making poor contact.  I suppose someone has mentioned the relays?  I know that almost every electrical connection problem I've had on my Guzzis occurred when I was riding it or had just ridden, but not actually heat related.

[Chuck in Indiana]

^^^^ John makes a good point about the relays. Many running problems on V11 Sports are caused by dodgy relays, especially the aft two in the stack. Make sure they are good ones, and the relay bases are free of corrosion and making solid connection. DeOxit is your friend, here.

[Ronkom]

I had replaced one of the relays during the go-through before I sold the bike. The first time it died I pulled the trailer to bring it back to the shop, but replaced the rest of the relays first. It fired right up & ran fine...but of course it had cooled. I had barely gotten home when the phone rang w/news that it had quit again as the new owner was riding home. He said it lost power, began running very rough, then quit. Sounds like both cylinders. I've been through a failing coil, my SP would drop a cylinder...but keep running, nothing like this. Also been through a failing electric petcock...Sport already has a manual replacement.
Ronkom 

[Chuck in Indiana]

You really are going to have to determine whether it's fuel or ignition.
Remember Bike week back in the day when Mark and other volunteers were putting ice in the V of the new sports so they would start after they came back in? 
I don't think this the case, though. They always came back, but would vapor lock when sitting. This doesn't sound like your problem to me. I'm betting it's ignition. Like mentioned above, an inductive timing light will tell you whether it is.

[LowRyter]

another hint.  I carry a spare spark plug.  When I have a misfire, I like to determine if one of the cylinders is the culprit.  Then I pull the lead and install the new plug.   I can see if it's firing.  That way I can do it quickly and don't have to unscrew the plug in the cylinder.

[antmanbee]

The sensor is not expensive if you don't buy the part from Guzzi.

http://www.miparts.com/detail/rpm-sensor-engine-management_15598#.WotM7qinGUm

Also available on ebay from England for about $30-40.

[rodekyll]

another hint.  I carry a spare spark plug.  When I have a misfire, I like to determine if one of the cylinders is the culprit.  Then I pull the lead and install the new plug.   I can see if it's firing.  That way I can do it quickly and don't have to unscrew the plug in the cylinder.

I went a step further and soldered a pigtail with an alligator clip to a flat on the test sparkplug's nut. That way I can hook up the plug and ground it without having to hold it.  I drilled a shallow bore into the nut, tinned the pigtail, and heated the nut till the pigtail solder melted.

[Chuck in Indiana]

Ron, if you do go with a new sensor, the gap is .030"

[Vagrant]

relays and fuses can be erratic. my 2001 EV horns started acting funny this spring. I went to pull the fuse and it disintegrated in my hand. 2 others did the same thing so all got replaced. I cleaned the relays with deoxit. they were all replaced with good ones in 2008. you could hear one click when the horn button was hit but only got the horn 1 time in 3. I switched the relay out and problem solved. Just saying!

[Ronkom]

Pulled the fuses, Had a hell of a time getting the main 30amp one out. Found it had been so hot the plastic distorted....w/out blowing. Metal tabs obviously oxidized w/tiny shiny areas on the edges, (contact areas) cleaned tabs on all fuses. Ran the bike long enough to get hot yesterday, checking the sidestand switch, jiggling fuses, relays connections etc. while it was running...not so much as a sput.  Supposed to be warmer today, going to repeat test.
No responses to  readings taken on phase sensor as it was heated up, I assume it's OK.
ronkom

[Chuck in Indiana]

Pulled the fuses, Had a hell of a time getting the main 30amp one out. Found it had been so hot the plastic distorted....w/out blowing. Metal tabs obviously oxidized w/tiny shiny areas on the edges, (contact areas) cleaned tabs on all fuses. Ran the bike long enough to get hot yesterday, checking the sidestand switch, jiggling fuses, relays connections etc. while it was running...not so much as a sput.  Supposed to be warmer today, going to repeat test.
No responses to  readings taken on phase sensor as it was heated up, I assume it's OK.
ronkom

I responded.. sort of.. 

I'm no electrician, Ron.. but it sounds ok to me. Maybe Kiwi Roy will chime in.

The 30 amp fuse is a known issue. I'll do a little research and see what it causes..
Edit: that's not your problem, but needs attended to. It's just the fuse from the regulator to the battery.