Husaberg FE570 fuel/ignition problem

Facts:

• Husaberg FE570 2010 model
• Fitted with map switch
• I have fitted Acrapovic slipon (original manifoil/tubing)
• No faulty codes to read on Fi lamp when running

I built this bike from a de-mounted renewal project that had been still standing last 5 years. Some parts were missing, but as I built the bike I ordered the parts that were missing. Bike did not start when I had It ready for first test. Fuel pump were totally dead. I bought a new on eBay (KTM390 450 570 HUSABERG 125 2009 2010 2011 2012 2013 2014 IN TANK FUEL PUMP +KIT | eBay). Did not change fuel filter inside the tank.

The bike fired up and was working last winter for some few couple of rides.
Converted the bike to Supermoto wheels, added a Cordona quickshifter kit etc. this summer and bike was running all fine. Then suddenly I noticed a feeling of “running out of fuel” when backing of the throttle into traffic light etc. Then a long journey started….

• Un-mounted the quickshifter kit
• Took off the tank, looked over plugs and added some WD40
• Measured the fuel pump supply and resistance. All fine
• Mounted everything together and bike was running fine again
Then after a couple of days, the issue came back again, even worse than before
• Did everything from last tear-down again, but this time it did not work
• Suspected fuel pump, so got a new one on warranty. No change
• Suspected fuel issue, since no obvious spark fault issues after checking the spark signal
• Measured current draw from pump to 2,5 Amp (is correct)
• Reading electrical wire schemes and doing several test around ECU, All fine
• Checked all visible wires for faults
• Then I tried giving the fuel pump direct power from a 9V battery. BIKE RUNS JUST FINE !!!!
• Power the pump from bike harness, issue is still there.
• Tried unplugging map switch, and also the other setting positions
• Tried feeding the fuel pump 12V from separate battery, same issue.
• Opens the tank in both ends, running fuel thru pump from an ice box with fuel to check for leaks inside tank. No issues found here and bike till runs fine when 9V battery is used.
• Replaced the pressure regulator after suspicion of to low output pressure
• Replacing the fuel line from tank to injector with a new without quick connectors
• Measuring fuel pressure. 9V battery: 0 bar / 12V: 3,5 bar (correct). When 9v battery I used the pump barely runs, and no fuel in return from regulator. When run on 12V there is good pressure in the return line inside tank but still 3,5 bar on the output.
• Unmounted fuel rail and injector and mounted the injector on my stripped down tank setup. Suspected injector stuck in open position flooding the engine. Checking correct function on injector by opening this with separate 12V battery while running the fuel pump on 12V and measuring 3,5 bar output pressure. God spray and correct function on injector. (In my test setup I was not able to try the injector function when connected to the ECU so that function is still un-tried)
• In desperation I now changed the spark plug to a new to look for issues on the spark side. Same issue

I have also tried to measure some of the associated sensors, but this is difficult without having access to a diagnostic tool. The ones I have been able to measure ohm values have been inside spec. Have not been able do a full check to rule out TPS, lambda sensor, OAT sensor, manifold pressure sensor.

Seems like the bike will not run clean when 3,5 bar fuel pressure is applied, but runs great on idle when no pressure from the pump is present and the engine running on the vacuum fuel pull.

Any ideas what condition that can cause such issue ?

jon andersson said:

Maybe faulty injector. It could be that you are right about it not closing properly. Maybe the feeling of running out of fuel is the opposite? You are running way to rich when you cut the throttle? As you say with lower pressure it runs, with higher it doesn't.
Does it smell of fuel or any other signs of too much fuel?

If you want to check if the injector can hold pressure you can mount it to the loose rail and hold it in place. Then push the start button and see if there is a spray pattern. Then give gas and push start button again, now the injector should be closed and give no fuel at all.

Click to expand...

I actually connected and manually opened the injector with separate 12V battery. All was connected to the tank and was runing as it would have on the bike. The only thing I did not test then was with the open/close signal from ECU. Why shouldn't there be a spray when giving gas by the way ? Would have expected even greater spray when opening up the throttle...

paolo6 said:

Sounds like you've covered a lot ! Nice
Could it be the signal from ecu ? Maybe some wire went bad...the issue was sorted for a short ammount of time after spraying some w40, so why did it come back after? And it idle nice but not when you rev .even the injector not closing properly

It could be a lot more
I remember when I was at my mechanic that we call ktm because we couldn't figure out...ktm 690 bike start fine when the diagnostic from pc was connected to the positive of battery when we took it off it won't start...we end up having to send the ecu ktm ....it was so weird ....best of luck

Click to expand...

The signal from ECU was the one thing I did not manage to do when I had the test setup with the open tank system. That way I could see if the ECU is sending the right signals. My guess is that it will, because the bike would not run on the 9V battery if it was closed. The only thing I can see causeing this is if the injector is stuck open when ECU is connected and the "out of gas" feeling I've had actually is a rich running condition

Can TPS, Map switch, lambda sensor or any other electrical imputs generate an issue like I experice here ?

The problem in Norway is that the importer for the last 25 years sadly died earlier this year, and now there are no dealers or mechanics to get help from any longer