Suddenly dying at 2000 rpm

[John A]

If its not loosing spark it sounds like blocked air filter. we need more symptoms

[Chuck in Indiana]

This thread seems like an unintended advertisement for carburetors.  The advances in fueling and emissions made possible by FI can sometimes be offset by the occult mysteries involved in troubleshooting FI systems.  I hope I never have to get into my 390 Duke's FI.  Flawless to date, but fingers crossed.

I have had pretty good luck with carbs over the years, myself.    The Mighty Scura has been flawless, too.. until now.
I've just printed out Kiwi Roy's excellent V11 Sport ECU test point layout drawing, and am headed out to the shop.
Beyone here there be dragons.

[Unkept]

Beyone here there be dragons.

Easy there Bilbo!

[John A]

Does it die completely or will it come back if you close the throttle?

[guzzisteve]

You might try the old relays, even new ones go bad or are bad. Worth a try.

[Muzz]

I have found doing the Mystic dance of the Rubber Chicken around the bike can work wonders Chuck. Just remember to do it the opposite way to what you would normally do such dances as it did originate in the Southern Hemisphere.

[Chuck in Indiana]

Does it die completely or will it come back if you close the throttle?

No it dies completely. Instantly.

Steve, I have some new GCIs, I'll give it a go after a bit.

[guzzista]

Ignition switch ?. My 02 Ev  was shutting off suddendly under accel (dont recall what RPM). In my case the ignition switch  (electrical part bolted to ignition key cylinder ) had a bad contact that caused it to shut off..may be worth having a look

[Chuck in Indiana]

Hmmm, here's the test at the ecu plug.
2018-03-25_04-07-12 by Charles Stottlemyer, on Flickr

It has a power commander. Should I think about unhooking it? It appears to be wired in..

[fotoguzzi]

It has a power commander. Should I think about unhooking it? 

yes, those things are nasty.. tuned right a V11 does not need a PC..

I side with the cam sensor guys, could the gap have gotten larger when you put in the RTV? sensor can read pulse at lower rpm but not when it spins up? also inspect the wire from the sensor right where it comes out of the plastic, I had a short there once under the insulation.

[Kiwi_Roy]

I just went through an issue with a similar era Guzzi, it would run until it got warm then stop for a while.

I finally convinced the owner to attach a light to the two ECU relays, this can tell you a lot about what's going on
If the ECU relay drops out its an electrical fault before the ECU
If the Pump relay drops out it's the Engine timing sensor.
On his neither light dropped out as it stalled but the pump relay did a few seconds later pointing to a faulty timing sensor.

You didn't change the gasket on the sensor did you, the gap should be 0.6 - 1.2 mm

[Chuck in Indiana]

I just went through an issue with a similar era Guzzi, it would run until it got warm then stop for a while.

I finally convinced the owner to attach a light to the two ECU relays, this can tell you a lot about what's going on
If the ECU relay drops out its an electrical fault before the ECU
If the Pump relay drops out it's the Engine timing sensor.
On his neither light dropped out as it stalled but the pump relay did a few seconds later pointing to a faulty timing sensor.

You didn't change the gasket on the sensor did you, the gap should be 0.6 - 1.2 mm

Thanks, KR.. no, didn't change the gasket. Refresh my memory on how to hook up the lights, if you please..
Do those numbers I posted look ok to you?

[rodekyll]

No it dies completely. Instantly.

Steve, I have some new GCIs, I'll give it a go after a bit.

Not to belabor, Chuck, but have you determined what dies?  Do you lose spark?  Fuel pump?  Everything?  Does the headlight stay on?  What does the battery do during this?

[Chuck in Indiana]

Not to belabor, Chuck, but have you determined what dies?  Do you lose spark?  Fuel pump?  Everything?  Does the headlight stay on?  What does the battery do during this?

Seriously, it's hard to tell. It's instant. Yes the headlight stays on. I'm betting it loses spark, but I haven't tried it. Fuel pump isn't running when it quits. Battery doesn't care.
I'll hook up a plug tomorrow and make sure it's ignition but it certainly acts like it. I've never seen anything like it.. it just seems perfectly normal and stops running. No hesitation, nothing.
 There is a fair amount of stuff unhooked now, I'll fool with it some more tomorrow.

[Lannis]

Seriously, it's hard to tell. It's instant. Yes the headlight stays on. I'm betting it loses spark, but I haven't tried it. Fuel pump isn't running when it quits. Battery doesn't care.
I'll hook up a plug tomorrow and make sure it's ignition but it certainly acts like it. I've never seen anything like it.. it just seems perfectly normal and stops running. No hesitation, nothing.
 There is a fair amount of stuff unhooked now, I'll fool with it some more tomorrow.

Do you have one of the little widgets that you hold up against the spark plug wire and it flashes every time the plug sparks?   Mine's been a lifesaver a couple of times.   If the thing's still sparking for the three or four turns while the motor is spooling down, it's got to be fuel.   But it's hard to imagine a mode of failure that could cut the fuel off completely and instantly on both cylinders, no sputtering or anything, at a certain RPM ....

Lannis

[Chuck in Indiana]

That's my thought, Lannis.. but I will test it. Tomorrow.

[Wayne Orwig]

It has a power commander. Should I think about unhooking it? It appears to be wired in..

Yes, as quickly as you can.  I had a similar issue with a Power Commander.

[n3303j]

How is fuel pressure and delivery rate?

[Chuck in Indiana]

How is fuel pressure and delivery rate?

No idea..

[luthier]

So there you have it Chuck. Unhook the Power Commander.  Maybe they fail from unhooking the battery with a spike from taking a terminal lead off slowly and accidentally sparking it. Can you run it without the PC?

[Kiwi_Roy]

just wrap a small wire around the 87 pin of the relay and connect the other side of the lamp to chassis
the ECU relay lamp should go as long as the key is on, in neutral with the kill switch closed.
The pump relay lamp will come on for a few seconds when you turn the key on then again when the bike cranks and starts, should remain on.
If the bike looses pulses from the crank position sensor it will stall and a few seconds later the ECU will turn the pump relay off (light goes out)

The bike can backfire and miss if its losing the odd pulse because the injectors and spark get out of whack.

Update:
          11/ The reading you got for the sensor seems a bit on the high side at 703 Ohms but it might be ok,
You could try swapping the meter leads around, sometimes if you have a bad connection you get a different reading because the electrolysis adds or subtracts from the Voltage, it should be the same.
The pins from an old serial cable are the right size to fit the ECU connector.
The readings you get for the TPS can be different, someone told me the resistance values are not all the same, it's best to check that with a Voltmeter.
The Efiman document has always been my go-to for any ECU sensor information, most still applies to the later ECUs
http://www.dpguzzi.com/efiman.pdf

I agree on getting rid of the power commander, there's no need to have one with Guzzidiag available, if you need a map someone with a similar machine would be a good source.

[guzzisteve]

Chuck,   Want to see if the PC is the problem? Just disconnect the ground wire.

[Chuck in Indiana]

Chuck,   Want to see if the PC is the problem? Just disconnect the ground wire.

Oh, good one, Steve.. I haven't been out in the shop yet today to make absolutely sure, but the PC appears to be hard wired into the harness.

[Kiwi_Roy]

The PC should have a male & female plug the same as ECU, just plugged in like an extension cord.

At least that's the way mine was

[Chuck in Indiana]

The PC should have a male & female plug the same as ECU, just plugged in like an extension cord.

I'm headed out.. I'll take a picture.

[Chuck in Indiana]

Well, found some stuff it isn't.  Once I took the 4 bolts off the computer I could see the PC was just jumpered on. So I unhooked it. No change. Replaced the ECU and injection relays. No change.
Hooked up my fancy inductive timing light.. its dead.  Well, it's only 40 years old.. maybe they'll warranty it. 
Hooked up my el cheapo HF inductive timing light that I bought when I had my fancy one out in SoCal, and it's flashing away.
It stops exactly when the engine dies. Sounds like ignition, probably.
I'll try to rig up some of KRs lights on the relays next.

[PJPR01]

Hi Chuck,

Just another thought...the fuel downspout coming out of the tank on the left hand side, when I replaced the old fuel line with Scud's new version and I removed that downspout, it was clogged with a lot of debris, which made me wonder how much crap might be floating around in the tank.  Perhaps there is debris in the tank that is getting sucked into the spout and clogging the fuel flow at the rate of fuel that is needed at 2K RPM.

Also...how fresh is the fuel filter?  Possible it's clogged also...maybe a more likely candidate than the downspout if something is floating in the canister and plugging the flow...

[Wayne Orwig]

Hooked up my el cheapo HF inductive timing light that I bought when I had my fancy one out in SoCal, and it's flashing away.
It stops exactly when the engine dies. Sounds like ignition, probably.
I'll try to rig up some of KRs lights on the relays next.

So it is electrical.
Have you disconnected the sidestand switch?
A poor/bouncing relay contact may do that. I have had that on the old Digiplex ignition system.
And I assume you cleaned the timing sensor.

[rodekyll]

I forget -- did you say that you replaced all the relays?  If so (and assuming you got 5-pin relays in all positions) maybe playing musical chairs with the relays (esp 5 and 6) would help isolate the problem.

[John A]

at least it isn't intermittent. its absolutely dependent on 2K rpm so that points to cam sensor or software or bouncing relay