ST1300 Fuel Pump Troubles

RJWWL

Back on the week of Thanksgiving I went to ride my ST13 to work...1st thing i noticed when I turned to key was I was missing the distinct sound of the fuel pump. I had all lights and battery just came of the tender. I turned the key on and off several times and switch the off/run switch back and forth a couple times...said a few choice words then climbed on my other bike. As soon as I got home from work I went to check it out...and found that everything seemed to be just fine...what the heck? So I tried again the next morning and everything seemed fine so off I went...I got about 3 miles from the house when she fell on her nose. I pulled over and rocked the off/run switch a couple times (I was on the side of the interstate so I couldn?t hear anything) hit the start button and bike came back to life and for the most part has been fine since. About 2 weeks ago I went to start the bike and once again I was missing the distinctive sound of the fuel pump...this time is never came back. I checked the fuse then loaded the bike on the trailer to take to the dealership. 2 days later, dealer calls and say bad fuel pump. $875 and he gave me a 10% discount. He continued by saying that there is power to the pump and the pump does not work. Said that they would have to completely remove the bottom fuel tank and the rear fender has to be removed to get the tank out and they will have to order it. This was a Saturday and I was out of town and they were closed on Sunday and Monday so it gave me a couple days to think about it...I just didn't believe that it was a bad fuel pump. I picked the bike up and brought it home and started tinkering with it...I found the harness that the pump plugs into with 3 wires. 1 wire pretty obvious is the ground, while the center seems to be directly related to fuel gauge and the 3rd wire to the pump. When checked with a volt meter I found that there is no power to the pump but there is for the fuel gauge. I shaved a little insulation back and hotwired the fuel pump to the battery and it comes to life (pump not the bike) At this point I?m a little irritated with my dealership as it does not appear that they performed a thorough diagnosis and I cannot see a reason why you would have to remove the tank to remove the pump assembly. Thought I would post my story here to see what feedback I might get before I start taking things apart. I live in the rural areas of Kansas and inherently have mice in the garage so I?m hoping for something as simple as a chewed up wire but I?m thinking that I may have to remove some large components (fuel tanks, Air breather, etc.) so I can see more of the wire harness - Any insight?
I?m also wondering what components are between the fuse and the pump?I?m thinking there must be a pressure switch of some type and am also wondering which model of service manual would be recommended and where would be the place to acquire it?
 
Wow. You are absolutely correct, the fuel pump removal does NOT require the tank to be removed.

Sounds like you're on the right trail in following the wiring. I've not followed that wiring, but I think I'd monitor the voltage to the pump to make sure that it isn't an intermittent pump motor failure (find that instance when the pump doesn't run and ensure it has power). I'd also trace the wiring and find every connection, cleaning each, using dielectric grease, and ensuring full connection (I do not know without looking at my service manual where the connections are).
 
I would lift the tank and remove the air box. Mice love to get under the air box and have been know to chew a few wires in there.

Also the emergency shut off is in the run position correct?

Best service manual is from honda. Well worth the money.

If need be I am sure there are several of us who would ride up to help you find the problem.
 
Power to the fuel pump comes from the fuel cutoff relay.
This relay is gets power from the engine stop relay. The relay coil is grounded by the ECM module.
I believe that the ECM only allows the relay to close for a second when the engine is powered up, and then when cranking/running. So when the bike is sitting and not running it's normal not to have power at the pump.

As said above, it could be a intermittent fault in the pump.

Having said that, Make sure that the bike does not provide power to the pump by probing it when turning the ignition on. If 12v is not present work your way backward from the pump to see when the voltage goes missing.
Find the fuel cutoff relay (left side of the bike, in the relay and fuse nest, it's the one most to the rear and outside of the bike).
Turn the ignition on while touching the relay to feel if it clicks.

Then pull the fuel cutoff relay and check that it has ignition power at two points, a good connection to the pump and that a ground it present at the final tab when you turn the ignition on.

Follow the missing thing and you should be well on your way.

HTH,

Dani
 
Just to make you feel better, I just went out to fire up my bike and have the same symptoms. No noise from pump. Trouble code #12. My turn to hunt. Bike has been sitting for three months in the cold and there are mice in the garage. Oh Joy!
 
nldaniel said:
Power to the fuel pump comes from the fuel cutoff relay.
This relay is gets power from the engine stop relay. The relay coil is grounded by the ECM module.
I believe that the ECM only allows the relay to close for a second when the engine is powered up, and then when cranking/running. So when the bike is sitting and not running it's normal not to have power at the pump.

As said above, it could be a intermittent fault in the pump.

Having said that, Make sure that the bike does not provide power to the pump by probing it when turning the ignition on. If 12v is not present work your way backward from the pump to see when the voltage goes missing.
Find the fuel cutoff relay (left side of the bike, in the relay and fuse nest, it's the one most to the rear and outside of the bike).
Turn the ignition on while touching the relay to feel if it clicks.

Then pull the fuel cutoff relay and check that it has ignition power at two points, a good connection to the pump and that a ground it present at the final tab when you turn the ignition on.

Follow the missing thing and you should be well on your way.

HTH,

Dani?l
Click to expand...

Make sure the relays are fully seated. The rubber boot around the relay can hide the fact that it's not fully seated.

Schematic here LINK
 
Glenc said:
Trouble code #12. My turn to hunt. Bike has been sitting for three months in the cold and there are mice in the garage.
Click to expand...

Ooh yeah, #12 is the first of the four "you've got mice" codes. Congratulations on being this spring's first victim. Look at the wires for cylinder 1.

--Mark
 
Had mine running this evening... Smallville hit the nail right on the head. I have not had time to spend in the garage this week till tonight. I started by going thru all the relays checking connections and for corrosion etc. from there I lifted the tank and realized I was on the right track when I pulled my air filter out and it was full of what looked like pillow stuffing. from there I removed the rest of the air box (Had to stop and drill out one of the screws along the way) to find the rest of the pillow stuffing…after cleaning that out I realized that the black wire to the left front injector was missing a 3" section of it...I installed a quick jumper wire and she fired right off. From here I have to figure out how I want to fix it…the little bassturds left me with 3/8” of wire sticking out of the plug then there is the screw that I had to drill out that looks like I’m going to have to order. Anyway, thanks for the great advice guys.
 
You also need a new dealer, as already mentioned, the bottom fuel tank and fender do not need to be removed to get at the fuel pump, only the top tank has to be removed. The bottom fuel tank has a removable top panel that gives access to the fuel pump.

Glad you found your real problem.:cucumber1::strawb1::broc1:
 
You don't even need to remove the top tank, just the seat bracket .(the long screw , 4 screws + the one screw that holds the brake fluid reservoir) .

Removing the fuel pump assy takes about 10 minutes .
 
There is a replacement set of airbox screws with allen heads you can buy or you can build your own. I don't have the links handy but a quick search should turn up what you need. Better than the factory parts. Here is a link. See post #33 for link to where you can buy them.
 
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