Hitchcocks Forum

Hi All,

Re: RE Classic C5 500 EFI fuel pump continues to operate.

After a short ride today, i went to restart the bike and noticed that the fuel pump continued to operate, long after the usual 2 seconds (approx) as part of the fuel priming process. The bike will now not start, just turns over with the fuel pump whiring away.

I have established that the pump relay is operating, and there is 12v continuous at the fuel pump connector plug.

Should the ECU switch off power to the pump once the priming process has completed (a timed operation) then switch back on once the crank is turning?

Has anyone experienced this or can suggest a solution?

an explanation of how the system should operate will be gratefully received

thanks in advance.

Is fuel coming out? Not specific to your bike but doesn't a fuel pump continue to prime until there's a certain pressure in the fuel line?

The most obvious reason I can think of for a pump sitting constantly priming AND the bike not starting is that there's no fuel getting through.

The initial prime when turning on the ignition is a timed event controlled by the ecu. There are no fuel pressure sensors in the system. The pump has a built in release valve that opens at 40psi.
Every rotation of the crank starts the prime sequence again.
You also have two relays.
Power relay that supplies the pump relay and that that feeds the pump.
Possible a sticking relay?
Would have thought it would still have started though? Unless something else is causing the problem.?

The pressure regulator on the pump is just a spring & plunger affair, no electrical connection to the pump.
It just dumps excess 'pressure' back into the tank.
I don't think that there is any other fuel pressure related sensors in the system - I haven't found any on my 2009 model, but later ones may be different?

I think - don't know - that the ECU switches the pump on for a few seconds to prime the injector, then off until the engine is running.

Frank

I'm not really familiar with the himalayan, but I work on little Chinese bikes all day long.
Have you checked for a spark?
Is side stand switch ok, this cuts the spark on some models.
Or the embarrassing one, check the kill switch.

I have no personal experience on fuel injected Enfields but the symptoms are similar to a failed crankshaft sensor on a popular German brand of motorcycle... Assuming it operates the same way , timed prime before startup and then as described already pump runs when the crankshaft turns and sensor operates.

The "German brand" had an occasional problem with the wiring to the HES which would stop the pump/injectors from running and/or no sparks.
Very rarely would they fail to make progress.
I do think the op needs to check to see if he has a spark or not.

Thanks for the replies so far....
From the suggestion from Haggis, I've swapped the 2 relays (power and pump) but the same result. I've tested voltage to the pump relay and its 12V constant.

I'll check the basics (air, fuel, spark) today and report back.

thanks

Double check the wiring for any wires touching bare metal especially in the electrics box.
If the wire from the pump relay to pin 11 on the ecu is earthed the pump will run continuously with the ignition on.