Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > Sport Touring: ST4 / ST3 / ST2 > fuel pump problem

[wayned]

why does this always happen 2 weeks from payday when I'm skint ???
Anyway I digress,
I went to start the bike the yesterday it flew over ok but I didnt hear the fuel pump prime.
A few hours later (after work) when I tried again I noticed the starter motor was getting sluggish (no joy with the fuel pump) so I put the battery on charge. This solved the problem so I left the bike overnite and now have the same problem again. (The engine did start but stalled after a few minutes during warmup and refused to start thereafter).
The battery is fine (good charge) the relays under the seat click but the pump is lifeless. The engine flies over quite happily.
Any ideas??

[rockhopper]

Regulator or the connector near it me thinks. Perhaps its a blocked fuel filter causing the pump to draw too much current which has fried the regulator and possibly the pump. Start the bike with a fully charged battery and measure the voltage across it with the engine running at 3000 rpm. Should be about 14.5 volts.

[BEANO]

Originally posted by rockhopper
Regulator or the connector near it me thinks. Perhaps its a blocked fuel filter causing the pump to draw too much current which has fried the regulator and possibly the pump. Start the bike with a fully charged battery and measure the voltage across it with the engine running at 3000 rpm. Should be about 14.5 volts.

Sorry to point out the blatent , but if he cant start it hows he gona measure it at 3000 rpm

DID YOU GET PROBLEM SORTED

[philthy]

It flies - so I imagine that if you attach it to a glider winch and tow it into the air, then allow it to go into a steep dive it may well achieve 3000rpm on the descent, at which point you can measure the voltage reading.

I too had a sluggish starter motor - try keeping it in a damp place and feed
it on lettuce for a few days - you will really notice the difference - but whatever you do keep it away from salt.

It's obvious really if you simply apply some lateral thinking.

[748mart]

Sounds like a dodgy connection in the fuel pump wiring or dodgy relay.

I had a v similar prob at Brands & hot wired pump to get back out on track. When home I traced fault to be in the alarm unit (Datatool), the fuel pump connections where partially burnt out.

[John W]

philthy,

that has to be the best response I've seen in ages

Not very constructive, but made me laugh out loud here at work.
Luckly I've just put my coffee cup down !

I'd check battery first to ensure it is showing a sensible voltage when turning engine over. If its too low the ecu will shut off.

Then I'd try the fuel pump relay, followed by a length of wire direct to the fuel pump as others have suggested and see if that allows the bike to start.