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My '03 Road King has a fuel pump problem. It started doing this recently. Only has 17K original miles. She's bone stock, except for Vance & Hines pipes, with an 88" twin cam, of course. Out for a ride recently, after stopping at a local watering hole, she restarted for the ride home, when the motor died after a half minute of running, as I was backing her out of the parking space. I could not hear the fuel pump whirring inside the tank. Had her hauled home and later, after several days, and many checks on relays and fuses, she started right up. I didn't do anything serious or change any relays or fuses, just removed and replaced them to check them, and that did it. But just to be careful, I bought a new fuel pump relay and had it with me for the future. A week later, the same thing happened again. I replaced the relay, which had checked as working, with the new one, and the bike still did not start, with the fuel pump not coming on. Had her hauled back home again! The next day she started right up without any work or checks performed. Yesterday, I rode her around and when I got back home I shut her off in the driveway, and later I tried to move her back into the garage but she wouldn't start again! No fuel pump noise, fuel pump not working. Each time this has happened, I tried switching the ignition switch and kill switch off and on repeatedly to try and overcome the issue, but to no avail. Each time this failure to start issue has happened, it self-corrects about 8 hours later or the next morning, but it happens again later all by itself. The problem is definitely the fuel pump intermittently does not work. Fuses and relays check out okay, and all have been replaced anyway. I had switched off the kill switch as I usually do to cut the engine after a ride. When I tried to start her I heard a loud "ping" seeming to come from under the tank but it could have been anywhere on the right side. I just knew she wasn't going to start, and I was right. No fuel pump sound at all, and she won't start. What could this "ping" be? Any ideas? I'm thinking the loud "ping" is important, as well as the fact that it occurred as I turned on the kill switch. Each occurrence of this problem there is apparently no voltage to the fuel pump relay. But it returns later all by itself. The problem does not seem to be the handlebar "kill" switch, but maybe yet another relay in there somewhere? Or is that a solenoid noise I heard? It's a mind bender all right. The fuel pump just quits, then hours later it works again, then it quits again after a short ride, after an engine shut off, and an attempt to re-start. It runs for ten seconds, then the fuel pump quits again for up to 8 hours. A real and dreaded Harley-Davidson electrical gremlin. Question: does the fuel pump get its volts from the ECM directly? Or does the ECM shut off the ground wire from the pump? Is there yet another relay between the ECM and the fuel pump? What could be killing the voltage to the fuel pump? There are no bubbles being blown inside the fuel tank from a possible fuel line or fuel pressure regulator leak. I can either hear the fuel pump running when I turn on the ignition and she starts, or I do not hear the pump sound and she does not start. The quick disconnect/check valve under the tank works fine, no problems there. It is DEFINITELY the fuel pump not working, then later it works fine again. But why? Trying to find this intermittent trouble is very difficult, as any mechanic knows who can't duplicate the problem the customer is describing. Perplexing. I'm like a lot of you Harley guys, who doesn't have a $$$thousand$$$ or two to drop at the stealership! Thanks for your advice in advance!
As 2AMguy stated the lines in the tank have known to got holes in them so that pressure and delivery are affected. But what you described actually sounds to me like the pump itself is failing. Maybe after you stop and the heat of the engine heats up the pump area and fuel it breaks down, maybe it is just intermittent and works one time and not the next? But I would be removing the pump and troubleshooting.
The only other thing I might suggest is to try wiggling the ignition switch would it does not want to prime and see if there is a chance of a corrosion issue in the contacts.
Another thing to consider is - are there any safety features that may be messing you up - Kickstand switch, clutch switch? Not sure what your bike has but it's something to consider.
Last edited by MarlinSpike; Jun 8, 2022 at 04:42 PM.
It sounds like you're tripping a circuit breaker. Follow the clicking sound you should see one of these. I think it's under the seat on your bike.
They're like a fuse that resets after they cool down.
. Sometimes they get weak and trip easily, but most of the time they trip due to a short to ground in your wiring.
An easy way to check is with a test light. You should have power to both poles.
I checked the fuel pump hoses inside the tank for leaks, as you said, 2AM, there are none. No bubbles inside the tank when the pump IS running either. This problem is definitely an electrical gremlin of some kind. The pump is not working intermittently, after the bike is ridden about ten miles, and the motor is then shut off. Upon attempting to re-start, the fuel pump does not come on at all. Later, after sitting for 8+ hours, AND NOTHING MORE BEING DONE, the problem self-corrects and the motor will start, with the fuel pump working again. The problem then recurs, just as before, after a short ride, and then an attempted re-start. Thanks for your input. This is not a routine issue, however, not the usual hole in the fuel pump hoses, broken tabs on the fuel pressure regulator housing cover, plugged fuel line, out of gas, failed check valve, etc.
I'm starting to lean toward the ECU getting an intermittent sensor reading from an electrical component, like the Crank Position Sensor, that could be causing it to disconnect the ground to the fuel pump. Can anyone confirm this is the function of the ECU in such a case?
Last edited by TheNeonGuy; Jun 9, 2022 at 07:29 AM.
S-glide, I'm looking into your suggestion I might have a bad circuit breaker. Thanks! Question: does this circuit breaker operate ONLY on the fuel pump circuit? Because I have power on all systems of the motorcycle during the problem occurrence. The lights, radio, starter, ALL WORK fine, just not the fuel pump.
One other question: could I possibly have a bad/failing bank sensor? I understand this shuts off power to the fuel pump if the bike tips over, to kill the motor in case of an accident. Where is this sensor located? How can I test it?
Also, I read that "too many" 100 Year Anniversary models were produced, even well into 2004, to take advantage of the demand for the Anniversary models, obviously to make more money for the Motor Company. Who who can blame them? But stories of shoddy workmanship and chinese engine bearings and other cheap parts being used in the 2003 models are all over the place, and that is not good business. "Made in the U.S.A." is the living mantra of Harley-Davidson. What a stupid thing to do, using chinese crap in their motorcycles. Makes me sad.
What say you about this? Am I experiencing the result of greed and haste and cheap parts, NOT made in the USA?!
Last edited by TheNeonGuy; Jun 9, 2022 at 07:41 AM.
It still looks to me to point to a failing fuel pump. Works when cool and stops working when giving time to heat soak from the engine heat while sitting.
One way to tell for sure if it is the line inside the tank that goes from the outside of the tank to the fuel pump, is to fill the tank. If the bike runs fine with a full tank but doesn't run right or doesn't start at a certain level, it's the line. Hell, I'd replace it just because it's 20 years old and a known failure point. Also, when you remove the fuel pump plate, make sure you buy new screws with the washers to create a good seal. Buy a pair of dog-ear clamp pliers and use the factory dog-ear clamps.
Thanks, BigMike! Yeah I checked that fuel line, quick disconnect, and check valve right away. No issues there, easy to check, first thing I did, in fact. The tank is completely full of gas too. Made sure of that right away.
No problems with the fuel hoses inside the tank, no leaks, no holes in the hoses. Mileage is very low, at 17K, not enough wear and tear to rub a hole in the tube.
I'm getting a NO-GO on the fuel pump from the ECU, I think. It's cutting off the fuel pump due to a bad crank position sensor or a bad bank angle sensor, probably.
The problem is slowly being narrowed down to one of these electrical devices, thanks to great advice from all you knowledgeable Harley riders here on Harley Davidson Forums! Thanks!
Now I need to find out the best way to test the CPS and the BAS.
Keep the suggestions coming!
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2003 Road King fuel pump problem
