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-   -   Fuel Pump Problem Has me baffled? (/showthread.php?t=85648)

Jolley 22-Feb-2012 16:40

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 22-Feb-2012 17:29

Quote:

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 22-Feb-2012 18:27

Quote:

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 22-Feb-2012 18:35

is it the 1.6M-B ECU and which Chip

dunlop0_1 22-Feb-2012 18:48

Quote:

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! 22-Feb-2012 20:07

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.

dunlop0_1 22-Feb-2012 20:15

Quote:

Originally Posted by 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.


Brilliant. :D

Confirmed somewhat by this guy with the same problem.


http://www.google.co.uk/url?sa=t&rct...goJOEoOwG7FjXA

Gbyte666 22-Feb-2012 23:34

Wow, not seen you on here for a long time Shazaam, top tip M8.
Hope that helps Neil.
Dont think I'm going to make Brands as my rear shock is not back from refurb yet. Aiming for Snett to watch your dust. lol

Craig

bradders 22-Feb-2012 23:49

I may do C1 at Snett too Craig, I like it there :burn:

dunlop0_1 25-Feb-2012 14:53

Well some progress may have been made. After reading the link posted earlier the guy had exactly the same issues as me. Since I have changed I think every part on the bike I decided to take some resistance readings across the crank sensor and the spare one I used (don't know if it's relevant though). Both of them cold gave around 340 ohms and hot around 450 ohms.
Now compare this with a brand new one which started at around 450 ohms cold and went up to around 980 ohms when hot.
I figure like the guy in the link that the breaking down point of each sensor only kicked in when the bike got to around 180 degrees + hence my first track sessions being with out a problem. Once the sensor had got hot and spit the dummy out I don't think it recovered fully until it cooled again, which possible was not long enough in the 40 mins between sessions.

I'm hoping I had two duff sensors and the new one will prove my right tomorrow at Angelsey. Still taking an ECU wiring harness with me though.


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