Quota Non start when warmed up

[GeorgiaGuzzi]

So I go my Quota back together. During my initial shake down ride I stopped to put fuel in it. After filling it up it would not restart. It was leaking some oil, turns out I did not install an o-ring with the new tach sensor. I Installed O-Ring, properly shimmed the sensor. Still no start. I put the old but still good plug wires back on. Still no start. I started swapping relays with the horn relay. Ecu relay was bad. Ordered new relays from Greg Bender (awesome quality product!) and installed. Bike fired right up! Yay! So today I started the bike up, warmed it up, pulled up from shop to house. Turned bike off to go get my gear. Bike will not restart again!!! 😡 My next item to check is spark plug gap.

Any other ideas? The bike fires almost immediately but dies right away. Giving it throttle when it catches does not help, just results in a backfire or two. I’m approaching stumped.

[fotoguzzi]

By tach sensor do you mean the camshaft sensor? Are you sure it's properly shimmed?
Did you replace all relays? If not, do so and report back.

[GeorgiaGuzzi]

By tach sensor do you mean the camshaft sensor? Are you sure it's properly shimmed?
Did you replace all relays? If not, do so and report back.

The flywheel sensor. It’s on the left (drivers side) front area.

And yes, all relays replaced with quality new sealed units.

[flangeman_70]

I’ve been down this road on my Centauro.
The relays literally bend the contact tang, but you’ve replaced them. Open one of them up and take a look inside
The crank angle went next. It started intermittently when warm no start until one day it just stopped dead mid ride.
Luckily I was close to home, it was a shakedown, waited 40 minutes and got it started and it coughed and sputtered all the way home. I immediately ripped the tank off and measured the crank angle sensor and it was high resistance. Waited an hour or so and measured again and it was back to near normal.
New crank angle sensor installed with correct gap 0.6-1.2mm and haven’t had an issue since, knock on wood

Good luck

Adam

[Wayne Orwig]

You need GuzziDiag. It maybe tell you more.
Do you have spark? Carry a spare plug and put a plug wire on that during a no start.
Do you have fuel in the cylinder? Do you smell any fuel at the exhaust?

Don't trust the fuses either. They can get corroded. May be worth replacing.

[GeorgiaGuzzi]

Thanks Wayne, I’ll grab a spark plug to test when it happens.

Just an update. I checked the gap on the plugs. It was a little too large. .09 mm instead of .07. I regapped the plugs, and went for a spin. As soon as I pulled out of my driveway it cut out. Coasted to a stop, pushed it back to my driveway and rolled down the drive. It would not bump start.

The fuses all look good. I just have this feeling it’s something I’m overlooking.

I do believe I have fuel in the cylinders.

[Wayne Orwig]

When it is a no start, and you first turn on the key, do you hear the fuel pump?
As in, any chance it is something as goofy as a sidestand switch failing?

You can borrow my GuzziDiagnostic cables if you have a PC. But I suspect they won't help a lot.

[Kiwi_Roy]

The fuel pump will start and run for a couple of seconds when you turn the key On but It's fairly hard to tell if it's running over the clatter of the engine.
http://www.thisoldtractor.com/guzzi007/schematics/2000_Quota_1100_ES.gif
When the sensor (47) is working properly the ECU turns on relay (41) which powers up the Red/Black wire to liven up the pump, coils and injectors.
So all you need to know if the sensor is working is a simple 12 Volt light incandescent or LED I sometimes put one as a permanent fixture under the seat of my Guzzis,
All you have to do if the bike won't start is glance and you know a major part of the bike is working.

As Wayne says it could be the side stand switch or or something else in that circuit a 12 Volt lamp will tell you the state of that as well, my VII Sport was playing up one day, I looked under the seat and found the lamp across the petcock at half normal brightness. I was away again in seconds with the stand switch bypassed.

[moto-uno]

  Would you have access to another set of ignition coils ?  Peter

[tris]

Has the Quota got a TPS?

If so, has it
a) Moved
b) Gone FUBAR

The one on my B11 caused the bike to die at idle but run on the throttle until I replaced it

[GeorgiaGuzzi]

Wayne, I will check the side stand switch by bypassing it when it misbehaves. Also I’ll recheck the fuses and probably replace them.

Roy, I can hear my pump do it’s initial cycle but I have no idea if it remains functional after starting. That’s a good suggestion and I’ll see about adding a check light. I just wire it onto the pump leads correct?

Peter, not at the moment. I’ll look into the ignition coils after the pump.

Tris, I have no idea tbh. I’ll research and check.

Thanks very very much everyone. I’ll get to diagnosing this coming week.

[fotoguzzi]

Roy, I can hear my pump do it’s initial cycle but I have no idea if it remains functional after starting.

When it's running open the gas cap, if gas is swirling around you know it's pumping.

[Kiwi_Roy]

The initial pump priming has nothing to do with the sensor (the motor is not even turning), its strictly based on a timer, when the motor is turning over the ECU should see pulses from the sensor and turn the pump back on
Pick up a feed wherever you can off the Red/Black wire, there are easier places than off the coils. The light (38) for example or simply wrap a small wire around pin 87 of the relay.
Once you see how informative it is you will be reluctant to do away with it, imagine trying to get a meter onto the pump for example.
As I said earlier another really useful place to monitor is the signal powering up the ECU relay connector (51) loom from the rest of the bike, its often before there that gives trouble due to corrosion or loose connections.
Fuse 3 is a convenient place to monitor that signal in this case.
Get power to the ECU and chances are the bike will always run.

Note: the actual wire colour may not be Red/Black but you will be able to figure that out because it goes so many places.
The only other signal (52) going to the ECU is just pulses to the tach, not required for running.

[Bob Mehmen]

  Fuel taps fully open?

[Chuck in Indiana]

New crank angle sensor installed with correct gap 0.6-1.2mm

This. If there is too much gap, it will run poorly or not at all.

[fotoguzzi]

This. If there is too much gap, it will run poorly or not at all.

what he said in reply number one.

By tach sensor do you mean the camshaft sensor? Are you sure it's properly shimmed?

[Wayne Orwig]

Wayne, I will check the side stand switch by bypassing it when it misbehaves. Also I’ll recheck the fuses and probably replace them.

Roy, I can hear my pump do it’s initial cycle but I have no idea if it remains functional after starting. That’s a good suggestion and I’ll see about adding a check light. I just wire it onto the pump leads correct?

If you hear the pump with the key on, then the sidestand switch is fine.

Now you need to know about spark and/or fuel.

Carry a spare plug, sniff the exhaust for fuel.

[Kiwi_Roy]

To illustrate how important the ECU wiring is I have cut out just that part of the bike. It's actually a separate sub-loom just for the ECU and anything associated with it.

I have drawn a couple of lamps on it, the one with the * tells you that the coils and injectors are powered up and the pump should be running.
The pump starts for a couple of seconds when you turn the key on but that's only a simple timer to prime the pump. After that it relies on the Phase Sensor, this simple device is absolutely vital for the operation, it fires the spark and
injectors based on gaps in the Phenolic wheel, without a good phase sensor gapped properly you are dead in the water, the simple light gives you an indication that its working otherwise how would you know?
Sure if the engines running, it must be working but suppose its not, this simple light stops you guessing.

How do you know the Interlocks are ok
Another light on the interlock circuit tells you that by glowing at full brightness, not half bright or winking as it can if you have a bad side stand switch or other bad contact, Of course without good interlocks the phase sensor won't work either.

This same idea rings true for any modern Guzzi as well, very little has changed over the years in the fuel injection department.
This is all your Guzzi needs to run, it will get home without lights, starter, indicators and the horn, they are only window dressing for convenience. It will run just fine without the interlocks if you hot wire it, even the relays aren't required.

[GeorgiaGuzzi]

Thanks Roy. Much appreciated. I’ll tackle the items over the coming month. Between work, home improvement honey do, maintaining my other, and replacing the front suspension on my ‘97 Cummins I think I need a clone!!!

[Chuck in Indiana]

Nice, KR. Saved that one to my "Roy's Guzzi Stuff" file. 

[GeorgiaGuzzi]

Is this a light like Roy is talking about installing?

https://www.ebay.com/itm/254594648636

After I get back from my trip my attention will be back on my Quota

[Tom]

Gas filter?  If mounted on just above the engine.  You're getting vapor lock or it needs replacing.

[JayDee24ca]

Is this a light like Roy is talking about installing?

https://www.ebay.com/itm/254594648636

After I get back from my trip my attention will be back on my Quota

Those may work, but I used simple micro LEDs pigtails on my Quota ( I think Roy told me which ones to use) and they are about 5 bucks for a bundle of them, maybe 10 or 15 to the bundle. 
JD

[GeorgiaGuzzi]

Those may work, but I used simple micro LEDs pigtails on my Quota ( I think Roy told me which ones to use) and they are about 5 bucks for a bundle of them, maybe 10 or 15 to the bundle. 
JD

Thank ya, thank ya very much. (In best Elvis voice)

[GeorgiaGuzzi]

Okay, fuel pump is getting power after kill switch is switched on. It powers up for initial prime, then has power while turning over and when running.

When cool it started right up. Idled and runs well. After a trip up the driveway and on the way back down it got warmed up and promptly died. Fuel pump still has power when cranking over during non start. However, when I checked spark the left side spark plug has strong spark, arcing nicely on the crash bar. The right side spark however, has a very faint spark. No arcing, not bright, just a faint wee spark. I did purchase a very basic multimeter today. But I have never used one so further instructions for diagnosing this would be most welcome.

Cheers, Robert

[Tom]

After getting it warm. Try spraying some starter fluid or carb cleaner in both cylinders then start.  If it runs then you're not getting gas.  Maybe fuel filter needs a change-out.

[GeorgiaGuzzi]

After getting it warm. Try spraying some starter fluid or carb cleaner in both cylinders then start.  If it runs then you're not getting gas.  Maybe fuel filter needs a change-out.

I installed a new fuel filter while I was repairing the seals. But it sure acts like it doesn’t get fuel. What are causes of vapor lock? Would the fuel regulator being blocked up cause an issue? While I had the tank off I stored it inside but a dirt dauber had build a home inside the fuel regulator inlet. I cleaned it out as best as I could but turns out a replacement quota regulator is unobtainium!

[SmithSwede]

I like Tom's idea.  If adding fuel solves the problem, then something isn't right on the fuel side.

I'm also curious about the weak spark you reported on the right side when the engine is warm.  Do you also have a weak spark when the engine is cold?  I think ignition coils can sometimes get flaky when they warm up.

Can you swap the coils around?   Would be interesting if the weak spark appeared on the left side after swapping the coils around. 

[Tom]

My V11 Sport used to vapor lock.  The fuel pump was located in the middle of cylinders just above the block.  The cure was to relocate it with longer hoses.  You could try to insulate it more to keep heat away from the pump.

[GeorgiaGuzzi]

Smithswede good suggestion. Tom, the fuel pump and filter are under the seat. Should I insulate them anyways? Anyways, the rain just started in earnest so I’ll get started checking in the morning and post results. Thanks