Answer me this...

[dlaing]

One way the fuse might blow is if you pressure regulator is malfunctioning, or the fuel filter is clogged up.

A mechanic once told me that he could tell when a fuel filter needed replacement because it would put a strain on the battery.

Not sure if it is true, but worth a check.

[callison]

One way the fuse might blow is if you pressure regulator is malfunctioning, or the fuel filter is clogged up.

A mechanic once told me that he could tell when a fuel filter needed replacement because it would put a strain on the battery.

Not sure if it is true, but worth a check.

42560[/snapback]

 

Our fuel pump is on a different fuse. I can't give too much credence to the fuel filter/pressure regulator story. Either one could put the fuel pump (we are talking an EFI system here too I presume) into a mode where it's pumping hard, but I would think that if the pump were drawing enough current to blow the fuse because of the lack of fuel flow, the vehicle would already not be running. More likely, this story originated with a fuel pump running in an empty fuel tank that overheated and seized. That would blow the fuse in a most grand manner.

 

I'm betting that the powder coat is making for a bad ground. Since the bike is apart - again - I can grind some paint off at the voltage regulator mount point to ensure an adequate ground and hopefully that will fix the problem.

[Cliff]

When you block a vacuum cleaner the engine revs up as it is doing LESS work. The speed up increases the back EMF of the motor and reduces the current drawn.

 

A stalled motor however produces not back EMF and will draw a huge current.

[callison]

When you block a vacuum cleaner the engine revs up as it is doing LESS work. The speed up increases the back EMF of the motor and reduces the current drawn.

 

A stalled motor however produces not back EMF and will draw a huge current.

42593[/snapback]

 

Yup. And a seized electric motor draws maximum current. For a finite length of time unless the input current.

 

I had to think about Cliff's post for a second there. The fuel filter and pressure regulator are both downstream from the pump, so in this case at least, the pump will not be freewheeling like the vacuum cleaner example. I think the pump has it's own internal regulator/sensor though and simply shuts off or idles down when max pressure is reached. I mean, according to the schematic, it gets 12V all of the time when the circuit is energized, but it only runs hard for two seconds when the system gets turned on, so whatever is doing the two second throttle back must be integral to the pump. Oh wow. Two second throttleback. Sounds like were launching a space shuttle.

 

Can there be back EMF on a motor with the shaft stationary? I always assumed that would make it a straight inductive load and that counter EMF was only produced when something was moving. I has been a very, very long time since I was in electronics class.

[dlaing]

I imagine vapor lock could also cause the pump to stall and a fuse to blow.

Also if the magnets in the pump get hot enough for a curie effect to take place, stalling and blown fuses or pump could happen

Smokin'!

[TX REDNECK (R.I.P.)]

I imagine vapor lock could also cause the pump to stall and a fuse to blow.

Also if the magnets in the pump get hot enough for a curie effect to take place, stalling and blown fuses or pump could happen

 

 

 

The only way this could happen ,is if the planets were in proper alignment . And then only in the atmospheric conditions of Uranus

[dlaing]

The only way this could happen ,is if the planets were in proper alignment . And then only in the atmospheric conditions of Uranus 

42614[/snapback]

Yah, I could not find one google match that indicated vapor lock causing such a thing.

Let me go ogle ur anus and search for currie effect and vapor lock sorry, I lost it.

[dlaing]

According to Sunoco "To prevent vapor lock, the vehicle fuel system temperature must not exceed this temperature. The TV/L20 specifications range from 105°F in the winter months to 140°F in the summer months."

So it is no small wonder that vapor lock is an issue on our bikes.

 

As for a Curie (Currie?) effect, we would not be hot enough under normal circumstances, but there could be a compounding effect of hot fuel increasing fuel pump amperage creating more heat and more fuel vapor and the pump has to work harder and hotter and the fuel gets hotter and the amperage goes up and the engine runs leaner and hotter and so on until the bike sputters or the fuse blows.

Is the Currie effect sudden, like the freezing point of water? I don't know. From what I read the temperature might have to be more like Venus then Uranus.

So the Currie effect may be out of the question, but the vapor-lock is another story, especially if combined with a year old fuel filter.

[callison]

Pretty good Dave. We've taken an ECU fuse issue and turned it into a fuel pump current issue on what seems like the thinnest possible reasoning. I don't think the fuel pump can draw enough current to blow the fuse unless it has simply gone bad. Granted, it can't be ruled out, but I've simply never encountered anyone that has actually had or seen this particular malady. The reason is, if the pump were encountering that level of vapor lock, the bike itself wouldn't run. It's not likely the operator would leave the ignition on. Plus, as long as there is no vapor lock upstream of the pump, the pump should have enough force to pump gas past any bubbles or vapor lock. If the electric petcock is the vapor lock source and the fuel pump isn't getting any gas, the bike will still get shut down and probably in a far shorter time than it would take to overheat the pumpt.

 

Back to the ECU. I had a phone conversation yesterday with a bike shop owner. He just powder coated a bike frame and his charging system doesn't work at all. I just powder coated my frame and I'm having a problem with a fuse. I'm not monitoring voltage, so I cannot absolutely say that the voltage is running high causing the ECU internal voltage regulation to crowbar and blow the fuse, but that does exactly fit what I think MAY be the problem. The other fellow is going to do a better job of grounding his regulator and expects his roblem to go away. I expect that mine will do likewise.

[zebulon]

Ok I'm thinking of the sport which has a seperate fuse/relay for the ECU.

 

The V11 has just one for the fuel pump and coils.

 

In that case 5A is not enough. The fuel pump itself takes about 5-6A. The injectors don't take much. They're about 30ohm. The coils will take 5-10A but this is only for a few ms.

You should be using 10A or 15A

41897[/snapback]

 

I don't think the trouble is here.

 

On my 3 '4v' injected bikes the fuse is 5A and i had no trouble with it.

I put a 5 A when i put the transil diod

 

It is some friends who invent this to prevent the Sport / cnetauro / Daytona rs ecu blow !

 

My friends recommend a 10 A i try with 5 and never NEVER have problem even on the track

 

Verify , clean and perhaps change your ground point on the frame.

 

On the supertwin i had some troubles also due to a bad ground fixation point when i just finished the mounting 2 years ago.

[dlaing]

After reading your two wiring diagrams, I would not be certain of which fuse controls the fuel pump, but if you tested it, that is good enough for me.

The other condition you mentioned, accelleration, is consistent with vapor lock.

Many months ago, you also complained of vapor lock.

What did you do to fix it?

I suppose powder coating could put an invisible insulating barrier at your ground points, and I suppose it would not have to be invisible at the regulator, where you can't see much, and could have easily overlooked it.

I just don't think I have ever experienced a faulty ground causing a fuse to blow, but with an ECU I suppose, it may be possible or even probable, I don't know enough to know.

Good Luck.

[luhbo]

You should have a direct link to the battery for all your electric components anyway. On my V11 the voltage regulator f.i. has a separate ground cable. Last summer it came loose and I ended up with a flat battery, but not with shot components (like tiny ecus) or blown fuses.

I'm still curious. Please make sure to post the solution.

 

Hubert

[callison]

After reading your two wiring diagrams, I would not be certain of which fuse controls the fuel pump, but  if you tested it, that is good enough for me.

The other condition you mentioned, accelleration, is consistent with vapor lock.

Many months ago, you also complained of vapor lock.

What did you do to fix it?

 

I re-routed the fuel line to the petcock. As it became warm from the nearby cylinder, the bend collapsed and cut off the fuel. Not vapor lock at all as it turned out.

 

I suppose powder coating could put an invisible insulating barrier at your ground points, and I suppose it would not have to be invisible at the regulator, where you  can't see much, and could have easily overlooked it.

 

Nothing invisible about it. It's a very tough, nicely adhered layer of paint.

 

I just don't think I have ever experienced a faulty ground causing a fuse to blow, but with an ECU I suppose, it may be possible or even probable, I don't know enough to know.

Good Luck.

42635[/snapback]

 

A common approach to power supplies for electronic components is a feature called "crowbar". Technically, a crowbar is a dead short. For a power supply, it's a near dead short. For over-current conditions or over input voltage conditions, a semiconductor is placed into full conduction from the power input lead to ground which either trips the breaker for the circuit or blows the fuse.

 

So let's backtrack a few years to the Sport 1100i's/Daytona RS's. On those bikes, the regulator is mounted (bolted) to the fairing sub-frame which is in turn, bolted to the steering head of the bike frame. The mounting bolts for the fairing sub-frame ARE the ground return path for the regulator. Not a good thing. After a time, the bolts and the holes develope some corrosion. The corrosion is mostly resistive (and non-linear) early on. What this means is that in effect, there is a resistor in series with the regulator to ground (the bolt mounting connection is between the regulator and the frame). This is a very low resistance, especially at lower rpms where the current the regulator is passing back to ground (if any) is very small, so the voltage developed across it is probably not very large. At higher rpms, the regulator needs to dump more current to ground and the voltage across the bolt junction goes higher. At very high rpms (about 7000), the alternator is pumping out a whopping 90V or more (unloaded). I don't know what the loaded voltage is, but it is certainly higher than the electronics of the bike can handle (and this is why you don't run these things without the battery, it's the main load component). At these high rpms, the resistance across the fairing mount bolts can amount to several volts. Since these volts appear between the regulator and the real gound reference of the motorcycle frame, in effect, the regulator is setting it's output higher than normal. Output to the actual bike might be 20 volts for instance, while the regulator was thinking that its output was 14V because of the 6V developed across the resistive ground path. For the Sport 1100i's, this meant that the zener diode voltage regulator on the input of the ECU had to handle far more voltage and current than it could sustain. Usually, it shorted out, saving the ECU, but disabling the bike. A better design, just crowbars the input, blows the fuse and recovers. That is what I suspect the V11 Sport ECU does.

 

So, back to my V11 Sport. The regulator is bolted to a painted bracket that bolts to the front down tubes just like everyone elses. That frame now sports a nice tough powdercoat paint job. The bolts and lock washers that hold the painted bracket are not going to give good conduction through the powdercoat. So, in the same fashion as the the fairing sub-frame on the Sport 1100i's, I now have a resistive ground. When I wind the engine up rapidly, the ECU fuse blows. Since the ECU functioned normally before the paint job, there is no reason to suspect that the ECU itself has a problem. As for vapor lock? Uh uh. This happened one block from my front door and the outside temperature was in the low 40's (Fahrenheit). Not exactly the conditions one would count on for vapor lock since there wasn't time enough for the engine assembly to reach an appreciable operating temperature and the outside temperature would not have been a contributor at all.

 

When I get my transmission back and re-assemble the bike (again), I'll grind some of the powder coat off at the mounts and I will also add a ground lead to the regulator straight to the engine block. That should take care of the problem. Powder coat is tough, it takes a grinder to remove it. No wonder the lock washers can't get enough bite to make a good ground.

[TX REDNECK (R.I.P.)]

Carl, I seen Vinny do the same thing on O.C.C. He used a razor blade to peel the powdercoat off where he needed a ground

[callison]

I'm going to use my Dremel tool. Every time I carry something sharp, I hurt myself with it Ambi-klutztrous digitally dyslexic I am...