Fi Fuse Keeps Blowing... Why!?

[ggathagan]

Last Sunday my 2001 died about a half a mile from home.
The gauge cluster didn't lose power, just looked as you would expect; like the ignition switch was on, but the engine wasn't running.

After pulling over and letting it cool a bit, I tried to restart it.
The lack of a fuel pump whine was a major clue, so as expected, the engine turned over fine, but no joy.

I pushed it home, let it cool down, drained a majority of the gas and went through the fuel pump troubleshooting procedure.

12v at the fuel pump connector? Nope!
Excellent! Don't have to buy another fuel pump!

Found that the 20A B fuse for ignition, fuel pump, and F.I. had blown.
I replaced it, still not knowing what the cause had been.

All was well until last evening.
A half-hour after leaving work, the same thing occurred.
I had been in stop-and-go traffic, up until then, and had just gotten on the highway.

I replaced the fuse again and went on my way... for about 200 feet.
Rinse and repeat two more times.

Called my roommate and about an hour later, he arrived.
Tried the same process two more times with the same result.
So I had it towed home and started in on it again this morning.

After replacing the fuse, the bike started and idled without issue.
I let it run 15 minutes, until the engine temp was around 185.
I then took it around 8K and held it there for about 5 seconds without issue.
In 1st gear, on the center stand, I revved it up to 5K and held it there for a few seconds. No problem.

There's always *some* vibration, so if a wire is shorting somewhere, I would expect it to show up under those circumstances.

That leaves one of the components loading up the B fuse circuit.

As far as I can tell, these are the components that are powered by or involved in that circuit:
Engine stop relay
Fuel cut relay
Fuel pump
Ignition coils
Fuel injectors
Purge control solenoid valve
Intake duct control solenoid valve
Exhaust air injection solenoid valve

The engine stop relay contacts energize the circuit, but its coil isn't powered by the circuit.
I wouldn't expect failure of the fuel cut relay to blow the fuse. Stop the bike, but not blow the fuse.

I believe the fuel pump is a constant load.
Is that a correct assumption?
If so, it wouldn't matter what else was going on; if it was the culprit the fuse would blow immediately.

I don't think the fuel injectors and ignition coils would be impacted by the absence or presence of a load on the engine. The electrical load they present varies by RPM, correct?

I don't know if the three solenoid valves are an on/off type of load or if they're a variable load.

Any relevant thoughts and ideas are welcome.

[KevCarver]

The smartass in me wants to say it must be the Wolf, so remove and ship to Knoxville...

Check out all your wiring from that circuit. Cold be a pinched or split wire that is shorting to the frame intermittently. Hitting bumps, wire stretching with suspension or steering, etc....

The last three on your list are PAIR system components and flapper? Easy to disable and won't throw a code.

The first two relays shouldn't have any issues while running? (I'm guessing)

Probably right about the fuel pump once the engine is running. It provides constant pressure which the fuel pressure regulator regulates to the fuel rail.

Unless of course any of those wires are shorting...

[ggathagan]

Kevin,

I did end up taking off the Wolf and putting the stock under seat tray back in.

The way I had the various fuse boxes and bits tucked into it with the Wolf under seat tray made it close to impossible to get to any of the fuses.

Since getting it fixed is more important right now, the Wolf stays off.

If you lived closer, I'd let you borrow it...

It's certainly possible that wiring is at fault.

The tow home last night could have shifted the wire back so that it's not currently shorting.

I'm borrowing a friend's truck later today.

Once I replenish my supply of 20A fuses, I'll disconnect those three solenoid valves, take it out for a spin around the neighborhood and see what happens.

[gll429]

sheesh!

do yourself a favor and trace the wire loom and dont asume!!

2nd. get a freakin circuit breaker replacement that fuse! get a long one and shave the tang/blade to fit if needed to be pressed in a tight spot.

[Cogswell]

I've thought about getting one of these - they seem to get good reviews.

http://www.amazon.com/Power-Probe-ECT2000-Circuit-Detector/dp/B000P6UO2I#Ask

They make some other products as well that would be nice to have in the toolbox.

[ggathagan]

sheesh!

do yourself a favor and trace the wire loom and dont asume!!

2nd. get a freakin circuit breaker replacement that fuse! get a long one and shave the tang/blade to fit if needed to be pressed in a tight spot.

Clearly, that is a logical part of the process.

This is my only mode of transportation, so my time frame is narrow.

I don't have the option of a tearing it all down and leaving it that way for a long period of time.

As such, I'm trying to eliminate as many variables as possible before starting the tedium that is wire tracing.

I've never seen the circuit breaker replacement. Definitely handy for situations like this.

I've thought about getting one of these - they seem to get good reviews.

http://www.amazon.com/Power-Probe-ECT2000-Circuit-Detector/dp/B000P6UO2I#Ask

They make some other products as well that would be nice to have in the toolbox.

Just watch a demonstration of the ECT2000 in action.

https://www.youtube.com/watch?v=15S0jzHfIt8

You still need a multimeter or something similar to find out which circuit is shorting, but being able to find the location of a short is impressive.

I've spent a lot more money on far less useful stuff.

In looking at the schematics, I realized that the purge control solenoid valve is part of the EVAP system of the California-model bikes, so that's only two solenoid valves to worry about.

[KevCarver]

In looking at the schematics, I realized that the purge control solenoid valve is part of the EVAP system of the California-model bikes, so that's only two solenoid valves to worry about.

Ah, that's why it didn't sound familiar to me!

I had forgotten how much different the undertray for the Wolf is as compared to the OE. So my smartassery wasn't totally unfounded. That whole thing is metal, so maybe something chafed?

[highsider989]

I would really like to hear the end of this saga..

[maxredline]

A simple ground fault may be your problem but.....I was having FI light problems and the bike would die but started again,usually within 10 minutes, but I never had a fuse blow. It happened twice on a trip, I din't wait for it to happen a third time. I ended up beefing up most or all of the grounds on the wiring harness. If you don't already know the Achilles heel on the viffer is the electrical department.

Even if this is not the fix (IMHO) you should beef up your grounds to make the bike reliable as it can be.

The orange coloured ground block on the side of the bikes frame, soldered it together. A vrfness wiring bundle does not hurt to help your rectifier regulator (one of the weak links) but beefed up grounds here to the frame are a must. Make sure your battery ground to the frame is clean. I also cut the 2 grounds from the egu and added new lines directly to the frame. Have not had a problem since.

There are a few post regarding this issue. Knowing that the electrical can go south its a great piece of mind.

Good luck

http://www.vfrdiscussion.com/forum/index.php/topic/77774-fi-light/?hl=%2Bfi+%2Blight

[Dexter]

Had this happen on my 98 VFR - main fuse blew several times - it was a bad Rectifier. Eventually the R/R died completely and I could ride the bike for about 30 to 40 minutes on

a full battery charge from my battery tender. I am replacing the R/R this weekend.

[VFGRERR]

Hey GLl429,

You gave me some good advice before with my vfr's electrics. Those fuse breakers sound a good idea. Have you got a image of one. I think I'mgoing to replace my fuses with them on my bikes

[ggathagan]

Had this happen on my 98 VFR - main fuse blew several times - it was a bad Rectifier. Eventually the R/R died completely and I could ride the bike for about 30 to 40 minutes on

a full battery charge from my battery tender. I am replacing the R/R this weekend.

The fuse that blows is not the main fuse. it's the 20A fuse that supplies the voltage for:

Fuel pump

Ignition coils

Fuel injectors

Intake duct control solenoid valve

Exhaust air injection solenoid valve

In addition to those components, the only other devices in the circuit are:

Engine stop relay

Fuel cut relay

the ECU.

As mentioned earlier, the two solenoid valves are a part of the PAIR system and I've removed them.

So we have:

Fuel pump

Ignition coils

Fuel injectors

Engine stop relay

Fuel cut relay

the ECU

As also mentioned earlier, the bike will idle for as long as I want.

I've left it running as long as a half hour without issue.

It can also be revved to 8K rpm and held there without issue.

Same goes for putting it in gear (on center stand) and revving it to 5K.

If the injectors, ignition coils, fuel pump or the two relays were the problem, the fuse would blow regardless of RPM or load.

That leaves the ECU or a short that only comes into play when enough vibration is experienced.

I tried running around the neighborhood in 1st gear at around 5K to see if I could reproduce the vibrations. No luck.

A simple ground fault may be your problem but.....I was having FI light problems and the bike would die but started again,usually within 10 minutes, but I never had a fuse blow. It happened twice on a trip, I din't wait for it to happen a third time. I ended up beefing up most or all of the grounds on the wiring harness. If you don't already know the Achilles heel on the viffer is the electrical department.

Even if this is not the fix (IMHO) you should beef up your grounds to make the bike reliable as it can be.

The orange coloured ground block on the side of the bikes frame, soldered it together. A vrfness wiring bundle does not hurt to help your rectifier regulator (one of the weak links) but beefed up grounds here to the frame are a must. Make sure your battery ground to the frame is clean. I also cut the 2 grounds from the egu and added new lines directly to the frame. Have not had a problem since.

There are a few post regarding this issue. Knowing that the electrical can go south its a great piece of mind.

Good luck

http://www.vfrdiscussion.com/forum/index.php/topic/77774-fi-light/?hl=%2Bfi+%2Blight

You're certainly correct about the VFR being infamous for poor grounding and deficient wiring.

The problem you're referring to, however, is a lack of proper ground.

My problem is the opposite: something is causing either a short or a large enough demand for current to blow the fuse.

I would really like to hear the end of this saga..

Well I fixed the problem, sort of.

To be more precise, I found a solution to the problem:

Last March, a friend of mine asked if I was interested in purchasing his '01 VFR.

He hadn't ridden it in over 2 years and felt like it was going to waste.

Ethanol in the gas ate up the plastic/rubber portions of the fuel pump assembly and the injectors were gummed up.

Other than that, it's in excellent shape, with just over 13K miles.

We replaced the fuel pump and swapped out the injectors for a rebuilt set and it was good to go.

Eventually, I plan on tracking down the problem, but at least it's not creating logistics issues.

[wagzhp]

That's cheating!

But is a very nice find.

[LangoPTC]

That may just be the most expensive fix I've ever heard of. Congrats!

[Auspanyol]

I've been known to use that method too... Except I moved on to a 6th gen...

Electrical issues suck the pus!!

[highsider989]

LOL.. electical issue, buy a new bike. Awesome. I can't wait to hear what you find.

[lanesmatb]

These type of intermittent problems can drive you nuts.

You nailed the issue at the beginning IMO, you have a chafed/exposed wire causing a dead short. It may be aggravating, but a careful examination of the wiring downstream from the fuse should find your problem.

Good luck.

Scott L.