V11 Sport 2001 intermittent stalling

[Tinus89]

Thanks for all the responses! This proves how great this forum is:).

 

 

How is your tank breather? Fuel filter? Valves?

I'm sure valves would have to be way out, but you never know.

 

Breather is fine, it's not tank suck (I checked). Replaced the fuel filter 3000km ago.

I have done the valves about 500km ago, after re-torqueing the heads (paper foot gasket). But as it is so easy, I will check again!

 

I know you said you visually inspected all connections but in this case I would really focus on the fuel pump connections. I.e. Take apart connections and clean with contact cleaner. I've found mine with some corrosion before.
You seem like you know what you're doing, we can get this!

 

Do you mean the connections on the pump itself? Because I checked those. If there are other connections somewhere in that line, let me know.

 

I concur with czakky. You're going about this the right way.

 

So, as we say clinically, "What's Next Most?" . . .

 

 . . . fuel pump/ connections, fuel filter, fuel line too close to the cylinder/head, faulty electric petcock, failed tank vent (tank suck)  . . .

 

As above, fuel filter is fresh and connections on the pump OK. Are there other? Fuel lines are as they have been for 2 years: router far away from the heads (and I have driven way hotter days ánd it happened while doing 80kmh for at least 4-5min straight, so I don't suspect heat to be the issue.

I have a manual petcock and ruled out tank suck.

 

A few suggestions:
The backfiring then dying might be related to

 

1/ Valve clearances,

2/ Induction Rubber Sleeves,

3/ Ignition coil or ignition lead faults.

 

1/ a sputter, cough problem when very hot can be caused by too small valve clearances holding the valves open. After a run the engine is hot, but when you stop, with the engine idling, the temperature continues to rise because air cooling is limited without forward speed. This is often overlooked. Valve clearances set too loose is better than too tight. See http://www.v11lemans.com/forums/index.php?showtopic=19610 for valve clearance setting advice.

 

2/ The engine is very sensitive to air leaks in those short rubber sleeves between the cylinder heads and the throttle bodies. Cracks so small you can barely see them can let in air, though this affects low rpm the worst. Air leaks may be worse when the engine is hot. Just a guess on this one.

 

3/ Corrosion at the ignition lead connection to the coil can affect the engine at higher engine loads.

Look for cracks in the ignition coils. Cracks can cause problems as temperatures increase.

If the coil/leads/plugs are dirty, then a tiny amount of rain or mist can make the dirt conductive, so the high voltage shorts to ground instead of through the spark plug.  

Feel for a cool cylinder to identify which side has the problem.

See also  http://www.v11lemans.com/forums/index.php?showtopic=12326&page=7&do=findComment&comment=151210

 

Gio also made a good suggestion on post # 12 of this thread. Fuel vapour lock is a problem if you have an external fuel pump.

On my bike, when I tried to restart after a fuel stop, the engine backfired and popped one throttle body out of the rubber sleeve. Look for fuel hoses touching the cylinder head, and think about fitting insulating sleeves or reflecting foil to the fuel pump and inlet hose. 

http://www.v11lemans.com/forums/index.php?showtopic=17560

http://www.v11lemans.com/forums/index.php?showtopic=17999

 

 

All rubbers are in prestine condition. I had set the valves to .18 and .22 mm, but I will check again!

Ignition leads are free of damage and corrosion. Are the coils one or two separate ones? Because it happens on both cilinders at the same time.

I will visually check the coils for cracks and check the wire loom connection. Is it one connection or more? Which connection on the wireloom side do I use for testing the 3ohm resistance?

 

So in short, I will do this and get back to you:

- Check valve clearance

- Check coils and measure resistance of coils and leads/plugs.

 

 

One important note: when I said backfiring, I meant popping in the exhaust. I will edit that in my previous post. It only backfires when I stay on the trottle when it starts surging (because I can't stop there for example. But mainly it pops in the exhaust, not back into the injector housing.

[Chuck]

 

 

- When I pull the clutch as soon as she surges and close throttle, she idles like nothing happened. When I open the trottle again (2-3k rpm, no load) she starts backfiring popping into the exhaust and eventually dies.

If you read through the spine raid report I posted yesterday, I dealt with that the whole trip. The issue was the CO trim set too lean. What is your's set at?

[Tinus89]

 

 

 

- When I pull the clutch as soon as she surges and close throttle, she idles like nothing happened. When I open the trottle again (2-3k rpm, no load) she starts backfiring popping into the exhaust and eventually dies.

If you read through the spine raid report I posted yesterday, I dealt with that the whole trip. The issue was the CO trim set too lean. What is your's set at?

 

 

Mine's set at 10 (and never has been different in the last two years)

[Chuck]

Mine was at +20 when it was running lean. I put it back to +40, and it's fine again.

It certainly sounds like the same issues I was having on this trip, but my engine/PC map may not equal your situation. 

At any rate, I'd look at reasons it could be lean. Air leak, etc.

[JBBenson]

I guarantee the TPS setting is out. Mine did the same exact thing.....

[docc]

Sounds like that is adding us to a "Decent Tune-up."

 

But, Tinus, I thought you would have already done that?

[stewgnu]

Still sounds like tps and/or inlet rubbers... plus have you cleaned out the butterflies? They do get crudded up some- must affect the initial opening??

[Tinus89]

Mine was at +20 when it was running lean. I put it back to +40, and it's fine again.

It certainly sounds like the same issues I was having on this trip, but my engine/PC map may not equal your situation. 

At any rate, I'd look at reasons it could be lean. Air leak, etc.

 

It could be wrong, but I can't imagine that causing such a sudden effect (and otherwise perfect running). She does not sneeze/pop or whatsoever, until she suddenly does.

I don't have a CO meter/gas analyzer to check it though...

 

I guarantee the TPS setting is out. Mine did the same exact thing.....

 

Nope, I had reset it a month ago and it still is where I left it.

 

Still sounds like tps and/or inlet rubbers... plus have you cleaned out the butterflies? They do get crudded up some- must affect the initial opening??

 

She is decently tuned. Also, if the above are wrong, would that not cause issues all the time instead of suddenly?

Also, when she starts acting up, it is a complete loss of power. When I keep the throttle open, she surges hugely, from no power to all power in seconds.

 

 

Update:

 

- Checked coils: no cracks. Measured them: 3.0 Ohm and 1.0 Ohm. Measured spark plug leads with 90deg caps on: both 5.8kOhm. I would say that should be OK.

 

Finding 1:

- Checked valves: they were too tight! Right were around (I/O) 0.10/0.18 and left (I/O) 0.06/0.10mm. Could that really be the issue? Apparently the gaskets compress more after the rebuild than I anticipated. I would guess that after re-torquing the heads it should be done, but it wasn't.

 

 

Finding 2:

- My intake fuel line is located quite close to the left cylinder. See also this picture:

 

Could that be the issue? It has never played up before...

I had relocated the fuel pump to above the spine already as you can see.

 

Finding 3:

- My 30 amp fuse has been rather warm...

 

Following this: I have noticed my indicators becoming quite fast on the highway (>4.5k rpm). Could the regulator becoming faulty? How do I check it? What voltage should it do at 3k rpm and what at 5k rpm?

[MartyNZ]

...if the above are wrong, would that not cause issues all the time instead of suddenly?

Also, when she starts acting up, it is a complete loss of power. When I keep the throttle open, she surges hugely, from no power to all power in seconds.

 

Finding 1:

- Checked valves: they were too tight! Right were around (I/O) 0.10/0.18 and left (I/O) 0.06/0.10mm. Could that really be the issue? Apparently the gaskets compress more after the rebuild than I anticipated. I would guess that after re-torquing the heads it should be done, but it wasn't.

 

Finding 2:

- My intake fuel line is located quite close to the left cylinder.

Could that be the issue? It has never played up before...

I had relocated the fuel pump to above the spine already as you can see.

From what you describe, it seems like there might be several problems. Once you have retorqued the heads and reset the valve clearances, it will be a little better.

 

Then comes fuel heating. Vapour lock explains your symptoms. Perhaps the area under the tank is acting as a little heat trap. Normally there is insulating panels on the lower surfaces of the tank to limit engine heat reaching the fuel inside. This tells us that it gets hot under there. If you try moving the pump away from this area, back to its original location, or above the oil cooler, then it may be better. Insulating the low pressure fuel hose and the pump is still useful.

 

I see that you have pod filters. What have you done with the temp sensor that was in the air box? It is important, and so is its location. See previous posts here: http://www.v11lemans...e=1?do=findComment&comment=218202 and

http://www.v11lemans.com/forums/index.php?showtopic=19764&hl=

The ECU cannot set the mixture correctly if the air inlet temp sensor is missing or located in a bad place.

[Tinus89]

 

...if the above are wrong, would that not cause issues all the time instead of suddenly?

Also, when she starts acting up, it is a complete loss of power. When I keep the throttle open, she surges hugely, from no power to all power in seconds.

 

Finding 1:

- Checked valves: they were too tight! Right were around (I/O) 0.10/0.18 and left (I/O) 0.06/0.10mm. Could that really be the issue? Apparently the gaskets compress more after the rebuild than I anticipated. I would guess that after re-torquing the heads it should be done, but it wasn't.

 

Finding 2:

- My intake fuel line is located quite close to the left cylinder.

Could that be the issue? It has never played up before...

I had relocated the fuel pump to above the spine already as you can see.

From what you describe, it seems like there might be several problems. Once you have retorqued the heads and reset the valve clearances, it will be a little better.

 

Then comes fuel heating. Vapour lock explains your symptoms. Perhaps the area under the tank is acting as a little heat trap. Normally there is insulating panels on the lower surfaces of the tank to limit engine heat reaching the fuel inside. This tells us that it gets hot under there. If you try moving the pump away from this area, back to its original location, or above the oil cooler, then it may be better. Insulating the low pressure fuel hose and the pump is still useful.

 

I see that you have pod filters. What have you done with the temp sensor that was in the air box? It is important, and so is its location. See previous posts here: http://www.v11lemans...e=1?do=findComment&comment=218202 and

http://www.v11lemans.com/forums/index.php?showtopic=19764&hl=

 

The ECU cannot set the mixture correctly if the air inlet temp sensor is missing or located in a bad place.

 

 

I had already retorqued the heads and reset the valve clearances, but it seems that the gaskets have compressed more afterwards...

 

Would you say that underneath the spine would be a better location for the pump?

 

The temp sensor I have relocated to underneath the seat, all the way near the fuse box. 

[czakky]

The regulator should be just over 14 volts at 3k RPMs and I think that it shouldn't raise any more.

[MartyNZ]

Would you say that underneath the spine would be a better location for the pump?

I don't know. That is where mine is, not perfect, but doesn't stall like yours does. See post #45 for previously mentioned thread 17560. http://www.v11lemans.com/forums/index.php?showtopic=17560

[Tinus89]

I just can't imagine it boiling the fuel with 23deg C outside... And also not while doing 80kmh (which is when it happened as well).

I dont feel like relocating the pump all the way forward. Not just because of the added work, but also because it puts it in a more exposed place, where rain can get to it easily.

 

 

What's the other people's feel for this? Just relocate the line close to the cylinder (on the pic in my hand) and replace the fuse, reinstall the tank and give it a retry? Blame it on either the fuse or the tight valves? Or relocate the pump?

Or is there anymore to explore?

[docc]

My pump is on the left side of the frame, filter on top. I groomed the pump as far forward in the holder as it would go, shortened the line from the petcock and shrouded in some heat reflective material.

 

This set-up allows a pretty gentle routing of the line to the filter. With your pump and filter so close together, I would be sure there is no "kink" as the line turns back.

 

Even at 0ºC, I wouldn't stick my tongue on those head fins.   

 

I think, with your latest round of remediation, you're ready for a test ride!

[Kiwi_Roy]

As Marty says check the high tension leads as follows
Pull the caps off the plugs and measure resistance to chassis, should read about 8,000 Ohms I think. Whatever it reads should be the same on both sides. This checks the caps leads and coils in one go.I see you have done that already

 

Don't discount bad plugs

 

I have seen a couple of times where the relay bases look just fine but a connector hasn't clicked in properly, when the relay is inserted it makes intermittent contact, easy to check just push on each one with a small tool.

 

One time when I had a bad regulator the bike would rev up, cut out, slow down a bit and repeat in a pretty consistent cycle but idled and low revs just fine.

I figured the ECU was cutting out on over Voltage to protect itself.