Flooding

[tricatcent]

I am calling this topic flooding, which really is a term for carburetors. My bike a 2004 Lemans has been running very well. Since December I have gone about 4000 Kms, with no trouble. I have Mistrals, stucchi and a power commander. I have set up the power commander with an air fuel ratio gauge. I found I had to set the low speed mixture a bit rich to reduce the low throttle opennig occasional misfires. I get 6.5 to 7 liters for 100 Km, which apparently is normal.

 

On Monday it was very hot. My bike started sometimes running on just one cylinder. When it does this it is obvious it is getting a huge amount of fuel to the right cylinder. Fuel can be seen pumping out the gaps in the exhaust system, on the right side only. Then sometimes it runs normally. I changed the spark plugs, because although they mostly looked white to light brown, on one side there was quite a dark and shiny band of carbon. That didn't make any difference. The spark seems quite strong anyway. There is so much fuel that must be the problem.

 

The plug wires seem to be ok.

 

I looked up other posts with te topic flooding and for some reason some of them mentioned the right side being effected only. One of the topics mentioned the solution to their problem was cleaning the contacts on the throttle position sensor. It seems that if the throttle position sensor was the problem, both cylinders should be effected. Some of the topics mentioned the cylinder head temperature sensor. This would effect both cylinders as well you would think. Also you wouldn't think it could have such a gross effect.

 

 

What do you think is wrong.

[raz]

I think most times a failing injector would be stuck closed, but I suppose it can stuck open too, in your case intermittently. You could try swapping injectors left for right and see if the problem moves with them.

 

That spark plug "shadow" phenonema is normal.

 

For what it's worth you can easily get down to 5 liters/100 kms with a carefully tuned bike, 7 l/100 km is the worst figure I've ever had. But that has probably nothing to do with your problem.

[Cliff]

I'd temporarily remove the PC just to eliminate that as an issue.

There could be a little dirt in the injector. Try running some injector cleaner.

[Dan M]

There could be a little dirt in the injector. Try running some injector cleaner.

 

Seafoam is an excellent gas additive for this.

Try tapping* on the injector while the motor is running. Sometimes this will dislodge the obstruction keeping the pintle from closing.

 

 

* easy, don't use a sledge hammer

[tricatcent]

Thanks for your advise guys. The bike ran fine this morning. It was only 70 degrees. It may have something to do with heat. I would love to get my milage down to 5. I will put some cleaner through, that can't hurt. Maybe the injector sticks open. That would explain the incredible quantity of fuel. It really was almost enough to make a puddle, except it evaporates to fast. I maybe I will buy a new cyl heat temp sensor as well. I don't want to add anything to that thread though. I am sure everything has already been discussed.

[Guest ratchethack]

I maybe I will buy a new cyl heat temp sensor as well.

IMHO, no need to needlessly throw new parts at this, particularly if it's an intermittent thing. There's no conceivable fault of the OE head temp sensor that could possibly result in fuel running out of the gaps in the exhaust -- on one or both cylinders.

 

There's also no conceivable combination of faults possible anywhere on the machine that could ever exhibit the symptoms you describe, other than 1. an injector mechanically stuck open, or 2. a FI signal fault at the ECU that results in a continuous "open" signal.

 

Per previous recommendations above, when in doubt (and whenever possible), best take the simple, cheap, and easy approach first. -- Run your favorite FI cleaner through it. No risk, low cost, high probability of success.

 

Good luck.

[GuzziMoto]

I have had a injector that would stick open. It caused the bike to run poorly, not the same way as you describe but that would be due to the bike having an O2 sensor (on the cylinder that the sticking injector was on no less). I would swap the injectors to see if the issue moves with the injector (meaning you have a bad injector) or if it stays (meaning you have a wiring fault or ECU issu telling that injector to stay open). If the injector is bad I would replace it. Usually if an injector is that bad it is not something that anything in a can will fix. I do not like being stuck on the side of the road.

[Guest ratchethack]

Just another thought.

 

With that much fuel dumping into the intake, it has no doubt washed down the cylinder walls (not good) and diluted/contaminated the sump oil. Best do an oil change.

[tricatcent]

The seafoam is working. I put about half a can into about 5 liters of gas, I ran to the gas station and filled it up with gas. It made a small improvement right away.

 

This morning my bike ran better than it ever had. It felt smoother. It did always have an occasional stumble at very low throttle openings. I had set the mixture a little rich to reduce this. The seafoam sems to have eliminated this problem. Maybe now I will be able to lean it out and get better milage. Once it is running well again I will put the air fuel gauge back on and see what I can do.

 

I think the right hand injector had been sticking open and also sticking closed.

 

This aftenoon when it got really hot I did have the problem again, but it went away pretty quickly. If it doesn't stop I will have to change the injector.

 

Thanks for the advise guys, Nigel

[tricatcent]

I haven't really fixed my problem with the right hand injector sticking open yet. It will still do it every once in a while I think really I will have to replace the injector eventually. The Seafoam did make the bike run better. It cleaned the injectors so well the bike started running richer. (I have an air fuel ratio gauge) I had to re adjust the TPS and the Power Commander to make it run properly again. I think the TPS had always been set to high and I had been compensating for this by leaning it out with the power comander.

 

I have found out though that if I add some of Lucas' Top oil that also contains injector cleaner, it eliminates the problem, until I fill up with a fresh tank of gas, then the problem returns until I add more oil to the gas. I think that almost any type of oil that would mix with the gas would temporarily solve the problem. Has anyone else ever had this problem.

 

Nigel

[GuzziMoto]

As I mentioned, I had an injector stick open (on a Buell) and the final solution was to replace it.

By this point the injector needs to be replaced in my opinion and anything in a can will only delay the inevitable. You could send the injector off to someone who actually cleans and flow tests them, but that could be more money then replacing it.

[Greg Field]

Listen to GuzziMoto. We unstick injectors all the time using a punch to deliver shock from a hammer to near the injector. I've personally revived 4 Guzzis that way. Seafoam's a start. Maybe try Techron, too, but the punch is faster. Just apply power to the injector and rap on the punch to free the sticky bastard. Or pull it off and send to a cleaner, but that'll cost you a bunch of time and money.

[raz]

Injector is Guzzi p/n 01530504, cost 388 Euro here. Also used on Ducatis (851/888, M900ie, SSie, ST2 etc.) and probably some cars too. It's called IW031 and native p/n is WFI191.

[Dan M]

How many miles or tanks of gas with the Seafoam?

The injector is a simple solenoid. If it is electrically good (not shorted or open both cold and hot), the only thing to make it stick is varnish. Running enough solvent through it will undoubtedly get it loosened up and working again.

It sounds like you are having some success cleaning it, keep at it a little longer before spending on another.

 

As others have echoed my comments in post #4, tapping helps but usually that will free one stuck closed. It sounds like your main issue is debris holding it open.

[Guest ratchethack]

How many miles or tanks of gas with the Seafoam?

The injector is a simple solenoid. If it is electrically good (not shorted or open both cold and hot), the only thing to make it stick is varnish. Running enough solvent through it will undoubtedly get it loosened up and working again.

It sounds like you are having some success cleaning it, keep at it a little longer before spending on another.

 

As others have echoed my comments in post #4, tapping helps but usually that will free one stuck closed. It sounds like your main issue is debris holding it open.

Howzabout the idea of taking out the injectors and sitting them in a pan of undiluted Seafoam, Techron or other favorite de-varnishing cocktail for longish periods of time, and/or applying voltage on the bench to open & close 'em whilst submerged?