V11 Sport 2001 intermittent stalling

[czakky]

Not a good start to a new model... Definitely experienced vapor lock in FL.

[Pressureangle]

Similar symptoms on my new-to-me '97 1100 Sport. TPS went out after 50 miles, lurching and backfiring. It quit altogether. New TPS and it's great! tune up the MyECU a bit, 'round the block twice or three, and... dead  quit with no warning. Pushed it back half a block, and after cooling a half hour it ran. Sort of. Came back cold the next day, fired like never before. Shut it before it got hot, checked the Cam sensor; .75 ohms. Ran until quit, 128*C. (quit while standing still, too) rechecked cam sensor, .08 ohms. Apparently shorts when hot. 

Must be Italian.

[footgoose]

 

Nice story Where did they lay it on? Can't avoid Baywatch pictures coming at me..

Anyway, hot day now, I'm off for soaring.

In the V. This was the first year, and vapor lock was rampant with them.

 

 

 

like Chuck said.... in the v, where it's hot

 

[Tinus89]

I did a "stress-test". Here is what I did:

 

- 23deg C outside.

- Went for a 20min drive to get her hot and returned home. Let her idle about 4 min, drive around the block (2min). Nothing. Let her idle another 2-3min and go again, immediate failure (coughing, popping in exhaust). Closing the throttle immediately kept her running idle. 

- Put her inside and hooked up multimeter. Rev until she died (~2500rpm), voltage does not go above 13.3v with headlight on. Felt ECU, battery and relays: all not hot.

- Hooked up Guzzidiag and started her again several times, checking TPS voltage, percentage and pre-ignition. Nothing strange happens when I slowly increase revs. She just dies.

 

Here is a video of me very slowly increasing throttle: (also note the clear metallic rattle still present as described in http://www.v11lemans.com/forums/index.php?showtopic=19627)

 

https://www.youtube.com/watch?v=LnTi_vtetIM

 

Any ideas? Cam position sensor? TPS?

[gstallons]

Figure out how to test the T.P.S. and test it cold and hot .

[Gio]

So not opening the throttle keeps the engine idling ... and from your video it seems to die quite suddenly (as in more of an" electrical" way) as soon as revs are increased. I don't think this is vapour-lock but certainly does sound like something is failing when hot ... testing the TPS sounds like the next step to me also but have no personal experience of how you might do that?

 

And yes - the metallic rattle can be heard also ...

 

All very strange and hope we can figure it out!

[Guzzi2Go]

It also includes the Voltage drop in the headlight circuit which can vary quite a bit.

 

Curious here...

 

What makes you say that?

[Kiwi_Roy]

Guzzi2Go,

                 The Voltage regulator senses the Voltage on it's black wire and decides if the battery needs charging based on that.

The problem is not connected to the battery Voltage directly, its connected to the headlight feed after the relay at a point half way along the tank. A small red/black wire is soldered to the headlight feed and the female bullet socket of the Male Female connector. On the bikes before 2000 the headlight relay is also in series with the start relay 87a contact.

Check your bike to see how much Voltage it drops, with the key On and headlight On measure the Voltage from battery positive to the red/black socket the regulator plugs into.

I have seen mine vary from 0.5 to 1 Volt mainly caused by the relays and sockets.

If your bike has been modified by adding headlight relays powered directly from the battery the drop will be very low.

BTW this is why you shouldn't ride with the headlight fuse pulled, the charging will not work.

 

If you have an after market direct connect regulator ignore all this.

[Guzzi2Go]

Hello Kiwi_Roy,

 

 the schematics I am looking at (Workshop manual) does not give me that. Yes, there is a red/black wire from the lamps (not only headlight, all(?) lights hang on it too) relay, but that one does not touch the regulator. The regulator is connected to the battery (+) via fuse F3 (30A) and there is a black wire (common ground, in addition to chassis) directly connecting the battery(-) and the regulator. Nothing is "sensed" there, nor does the regulator "decide" on anything. The regulator provides 14.6V "no matter what".

 

Hence the question...

 

BTW, the lamp relay is there to switch the lights off while you are cranking. Give you a bit of extra "juice". Nothing else.

[Guzzi2Go]

Back on topic.

 

Did you check air supply? The rubber connecting throttle bodies with cylinders may be cracked and you may be drawing more air then needed.

[Chuck]

Hello Kiwi_Roy,

 

 the schematics I am looking at (Workshop manual) does not give me that. Yes, there is a red/black wire from the lamps (not only headlight, all(?) lights hang on it too) relay, but that one does not touch the regulator. The regulator is connected to the battery (+) via fuse F3 (30A) and there is a black wire (common ground, in addition to chassis) directly connecting the battery(-) and the regulator. Nothing is "sensed" there, nor does the regulator "decide" on anything. The regulator provides 14.6V "no matter what".

 

Hence the question...

 

BTW, the lamp relay is there to switch the lights off while you are cranking. Give you a bit of extra "juice". Nothing else.

Remember.. you are looking at a Guzzi schematic which may or may not have any resemblance to reality.   

[Tinus89]

Back on topic.

 

Did you check air supply? The rubber connecting throttle bodies with cylinders may be cracked and you may be drawing more air then needed.

Yes, I both visually checked and using some brake cleaner while running (no rise in rpm). They are quite soft and in rather good condition.

[luhbo]

Figure out how to test the T.P.S. and test it cold and hot .

 

I don't think that a TPS is in any way heat sensitive. There's no electronics inside. Besides that, what would it be that could heat it up that much?

[luhbo]

 

Nice story Where did they lay it on? Can't avoid Baywatch pictures coming at me..

Anyway, hot day now, I'm off for soaring.

In the V. This was the first year, and vapor lock was rampant with them.

 

Yeah, something like that went through my mind You really don't know what you've missed so far 'till someone comes up with the right story. Wish I could have been there, watching them poking ice cubes under the tanks ...

But honestly, what noobs were resposible for this presentation?

There's a hose on the right side, open the clamp, let the fumes out and the show go one. It may be a bit messy sometimes, but hey, it's a motorcycle, it can smell a bit.

[bbolesaz]

 

Figure out how to test the T.P.S. and test it cold and hot .

 

I don't think that a TPS is in any way heat sensitive. There's no electronics inside. Besides that, what would it be that could heat it up that much?

 

TPS is a potentiometer, basically a resistor that has a sweep arm to move the connection and change the resistance. And yes, they often will go open with heat.  Depending on which side of the sweep arm the open is, the output will either go full on or full off.