Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > 998 / 996 / 916 / 748 > Fuel Pump Problem Has me baffled?

[dunlop0_1]

Yep all clear.
If the harness is a possible issue I was considering this.
The pump has a 12v feed when the ignition is turned on. The ECU then turns the earth on until the pump is up to pressure then turns it off. When the ECU gets a signal from the ignition sensor it turns the earth on again so the engine will run. So if I run a seperate fused/switched live from the battery to the pump and a seperate earth from the pump to the corresponding pin on ECU this in my mind would eliminate any of the existing wiring and possible problem?

[chrisw]

Chafing wire. Had the wire on the fuel pump connector chafing on the top the engine on my 999.

[antonye]

Also try a new fuel pump relay?

[Gbyte666]

I was going to say it sounds like the Pump Neil as I have just replaced mine, I had the same symtons as you. Misfire then ok, then sometimes wont start then nothing wrong at all then finialy packed in all together on a ride out, ( even the mighty Skids did'nt carry one of those with him on a ride out )
But reading down it seems you have replaced the pump ?
Sorry that was not really helpful was it lol
Get the meter out and rattle shake the bike about to see if the readings change drasticaly.

Craig

[Jolley]

Had a loose wire in a connector at Snett last year... Would cut ignition when the bars were turned right. The connector was pushed together ok, but one of the wires could be pulled out of it because the little metal tab on the end of the wire wasn't locked in properly. So maybe try pulling each individual wire out of every connector/fuse/relay/etc... I one pulls out it might be the cause.

[skidlids]

Originally Posted by dunlop0_1

Yep all clear.
If the harness is a possible issue I was considering this.
The pump has a 12v feed when the ignition is turned on. The ECU then turns the earth on until the pump is up to pressure then turns it off. When the ECU gets a signal from the ignition sensor it turns the earth on again so the engine will run.

Somebody rewired it then or is the test meter leads connected wrong as normally the pumps Earth goes directly to earth and the 12 volt feed is supplied by one of the engine management relays with the status of the relay controlled by the ECU, the same relay should also put 12 volts on to the coils at the same time as putting it onto the pump

[dunlop0_1]

Originally Posted by skidlids

Somebody rewired it then or is the test meter leads connected wrong as normally the pumps Earth goes directly to earth and the 12 volt feed is supplied by one of the engine management relays with the status of the relay controlled by the ECU, the same relay should also put 12 volts on to the coils at the same time as putting it onto the pump

Cheers Kev, I actually got that inf from ducati.ms. I've just made a temp harness which runs the pump on it's own. If it works when riding the bike it at least points me towards the wiring albeit from the relay's and or the ecu.

The biggest problem is i have to ride the bike for the problem to occur. Sitting the garage it's fine.

[skidlids]

is it the 1.6M-B ECU and which Chip

[dunlop0_1]

Originally Posted by skidlids

is it the 1.6M-B ECU and which Chip

Yes. I have a DP chip for the exhausts and 2 JHP ones aswell.

[Shazaam!]

The fuel pump supplies fuel under pressure as long as the crankshaft is turning. For safety, the pump is switched off by the ECU after about five seconds if the crankshaft stops turning.

So if the crank rotation sensor gap is incorrect such that it grows too large at temperature, the ECU will think the engine is stopped and shut off the pump. A cracked casing will also cause the gap to be incorrect at temperature.

If the sensor-ECU wiring or the sensor itself is faulty this can also result in pump shut-off.

Check the gap.