Intermittent Fuel Pump

[Kc5]

My FJR finally left me stranded.

I was going to run some quick errands around town, so I went to my shop, slipped on my helmet and hit the starter to let the bike warm up. I didn't fire up, but spun over fine. I turned the key off, sit down on the bike, turned the key back on, hit the starter and it fired up as normal.

About 3 miles down the road, I stopped for gas. After fuelling up, I had the no start condition again. This time I noticed that the fuel pump is not coming on. I could hear a relay click when I turned the key on, but no fuel pump. Everything else seemed normal. After 30 minutes of messing with it, I called for a ride to get the trailer and haul it home. This was a sad day, but not too far from home THIS time.

When I got it home, still no fuel pump. Pushed it in the shop and tried it again....nothing. Went inside for a bite to eat and came out to try it again and still nothing. I thought this was good, at least I'm where I can work on it now. I cycled the key one more time before I started to take stuff apart.

This time it starts right up. I started it and killed it several times over a 10-12 mile ride and never had another issue.

I can't afford to have this happen again on a cross country trip.

Any ideas on what to start looking for?

2012 w/15,000 miles

 

[Ignacio]

Several I can think of:

• Confirm the battery terminals are tightened?
• Review the technical problem list where you placed this thread including FJRF009.4?

 

[Donal]

I would be looking at replacing the fuel pump relay. The fact that it continues to run once started kind of points in that direction............

 

[ionbeam]

The FJR really hasn't had issues with the fuel pump or wiring unless it has been caused by the mechanic. Ensure that the fuel pump connector isn't broken and properly secured. The fuel pump relay is part of the Starter Cutoff Relay which has rarely had problems with all of the various circuits that pass through it.

You can play with the fuel pump via the diAG function by using actuator code 50 to turn on the fuel pump, it will be cycled 5 times and flash the Check Engine light. With no tools and little effort, anytime you want to troubleshoot or perhaps try to 'kick start' the fuel pump use the diAG actuator code. Read the how-to linked to this post, it's really simple to do. You may also want to look at error code history and see if anything got set in memory.

 

[Harald]

I vote for fuel pump relay as your first place to check. Back when I had my spider bite, I was checking all connections on the bike and found corrosion on the connector to the fuel pump relay:

If I remember correctly, it's located on top of the piece of plastic under the headlights that your fender would hit if it came up high enough. I cleaned up the contacts, slathered dielectric grease into the connector and put it back together. No fuel pump problems in 5yrs/70k miles since then and I ride in rain constantly. I didn't actually have fuel pump problems at the time, but that would have probably been the next electrical gremlin if I hadn't caught the corrosion early.

 

[Kc5]

I've heard that the fuel pump relay maybe be located in the front cowling or it maybe near the ECM under the seat. Can anyone tell me for sure where it's located before I start taking things apart and the best way to access it.?

After a combination of 14 or 15 start/stop and ride cycles, it bit me again. This time the bike had been sitting for about 2 weeks, I started it to let it warm up for a few minutes and killed it to go get my helmet. Two minutes later I tried to restart and the fuel pump didn't run. I lifted the tank and it appeared I had no voltage at the pump and then it did.

I've check most of the spider locations and they are showroom clean along with the battery connections. There are no trouble codes stored. I have no other problems at all. It appears that the fuel gauge shares the ground with the fuel pump and the fuel indicator reads accurately.

I'll take a look at the relay and connections if I find it.

 

[RossKean]

The pump doesn't run continuously! If the rail is pressurized, it may not run at all; especially if it had been running and you just momentarily shut it down.

If it didn't restart after the momentary shutdown, it wouldn't surprise me; especially if the engine had not been brought to operating temperature before shutdown. This behavior has nothing to do with the fuel pump or relays!!!! For some reason (theories abound but nothing definitive), the FJR does NOT like to restart if shut down without being brought up to operating temperature. The issue appears to be flooding and is normally "cured" by starting with WOT - sometimes several 10-second tries are needed.

 

[mcatrophy]

The pump doesn't run continuously! If the rail is pressurized, it may not run at all; especially if it had been running and you just momentarily shut it down.If it didn't restart after the momentary shutdown, it wouldn't surprise me; especially if the engine had not been brought to operating temperature before shutdown. This behavior has nothing to do with the fuel pump or relays!!!! For some reason (theories abound but nothing definitive), the FJR does NOT like to restart if shut down without being brought up to operating temperature. The issue appears to be flooding and is normally "cured" by starting with WOT - sometimes several 10-second tries are needed.

Very true.
Note that the pump will run for a second or so whenever the ignition is turned on, nothing to do with fuel pressure (at least on GenIIs).

 

[Kc5]

I didn't detail my problem well enough. This is a new fault, that appeared after 2-1/2 of ownership. I am aware of the potential short restart flooding and I know the fuel pump runs to pressure the rail and shuts off with the key on, until the bike actually is running/starting. Thanks for the tips, though. No sarcasm intended.

When this event happens:

1. I turn the key on and I do not hear the fuel pump running.

2. I hit the starter button and the bike will start for 1/4 second and die.

3. I hit the starter button and the bike will start for 1/4 second and die again.

4. Now it just spins over and the fuel pump is not running while trying to start.

At this point, I'm assuming that the 2 short starts, occurred because there was enough fuel and pressure in the rail for this to happen.

5. Raise tank, disconnect plug from fuel pump and insert meter leads into the plug and turn key on.......0 volts....when key is turned, but I can hear a relay cycle on and off.

6. Turn key off/on and no voltage appears.

7. Hold the starter button, motor spins, still no voltage.

I do this a couple of more times and then all of a sudden I have voltage at the fuel pump leads, when the key is cycled or the starter is engaged, like it is supposed to work.

I buckle everything and it works fine again......until next time.

 

[mcatrophy]

The fuel pump relay is within the so-called "Relay Unit" that contains another relay and several diodes to do with the start interlock system. On the 2006 & 2007 it's under the front fairing, right in the centre, but I believe it was moved to somewhere else, possibly under the tool-kit box? It has some 13 wires, colours (in no particular order) are:

Red/Black (engine stop switch)

Light blue/White (Neutral light feed)

Blue/white - two wires joined - (starter relay negative feed)

Red/White (From 10A ignition fuse)

Black/Yellow (from clutch switch)

White/Blue (from starter switch)

Brown/Red (From 15A Fuel Injection fuse)

Light blue (Gearbox neutral switch)

Black/Red (from clutch switch)

Blue/Green (side-stand switch)

Blue/Yellow (Fuel pump relay switch from ECU)

Red/Blue (Feed to fuel pump)

Incidentally, the same circuit that feeds the pump also feeds the injectors, if that feed was failing, the injectors won't feed fuel into the combustion chambers (though I suppose if there was residual fuel in there it might ignite for one power stroke? Dunno).

The 12 volt feed to the pump should be live whenever the ignition is on (provided neutral/side-stand/stop/clutch switches are consistent with engine running).

 

[Harald]

Although my problem was due to a spider bite, I did inspect all connections at the time and found corrosion in the fuel pump relay connection:

On a 2007, It's accessible underneath the headlights and ontop of the fairing plastic piece that your fender would hit if it could come up high enough. If I remember correctly, it can be unclipped from the rubber mount and pulled rearward to inspect. In my case, I had the whole front off the bike to fix my burnt S7 spider:

 

[Kc5]

It appears that I'm going to need a new fuel pump. I don't know if I've ever heard of one failing on an FJR, but I seem to have those unique problems.

I went ahead and replaced the relay unit, although I'm pretty sure there is nothing wrong with it. (On a 2012, it is located under the ECM, under the tool kit).

Apparently when the bike quit the previous time, my meter leads were not getting solid connections to the fuel pump plug and I got inaccurate readings.

While replacing the relay, I checked all of the potential ground spider problem areas. All locations, including the relay unit and battery, looked as if the bike just left the factory.

After putting everything back together, the bike started fine and I rode it for about an hour. When I killed it and hit the starter, it started right up. I came back an hour later, hit the starter and it started and died. It started and died two more times and then nothing.

As Mcatrophy mentioned, the fuel injectors use the same power feed as the fuel pump and they were firing until the fuel in the rail was depleted.

I lifted the tank, unplugged the fuel pump and was reading full battery voltage at the plug, when cycling the key. The plug and pump connections have zero corrosion.

I plugged the pump back in,turned on the ignition and the fuel pump sounded weaker than normal, but tried to run. I cycled the key again, fuel pump sounded normal and bike started and ran normally.

I'm open to any opinions, before I spend $500 on a new pump.

 

[mcatrophy]

When you read the 12v at the connector, are you going between the two contacts of the connector? If you are using some other ground to the meter negative, it could still be a bad ground connection to the pump.

Also, since the pump operation is intermittent, can you be sure you aren't simply not measuring an intermittent connection in the feed to it?

I once wanted to measure how the fuel gauge sender behaved, I was able to tap wires into its connector and feed a pair of wires out from under the tank. I could then run the bike normally and measure the sender. You could do a similar set-up with the pump connector.

Pics of how I did it here.

 

[Constant Mesh]

As an aside I wonder if the lean angle cut-off switch is misbehaving?

The ECU (computer) will stop the fuel pump and injectors when a bike overturns.

The ECU turns off the fuel injection system relay when the lean angle switch is tripped.

You could ground the coil return wire and actuate the fuel injection system relay manually. The ECU grounds or open circuits this wire to operate the relay.

 

[TownsendsFJR1300]

If the pump is questionable, Pull the pump.

You should be able to put 12 volts to the lines with the pump submerbed in water and see if it runs.( I'd slip the fuel gauge switch off the pump first for a ittle more room).

The pump should come apart after un-doing the plastic clips.

Below is a picture of a clogged up/failed FZ6 pump (single line, no return line).

You don't want to find this;

 

[Behmer]

Make sure your power connector plugging into the fuel pump has a tight connection. I had an issue on my 04 where I had power at the connector to the pump but the pump didn't always work. Must be a bad pump I thought... replaced it and the problem still occurred. I ended up tweaking the female pins on the connector to the pump a bit as a last resort in case of a bad connection and it has worked perfectly for many years now.