intermittent fuel pump

[LowRyter]

my local bike mechanic is working on a red frame V11 (not mine) that suffers from intermittent fuel pump failure.  I told him I would query the Guzzi community for any common occurrences.

 

I told him relays were a common electrical glitch.

 

I'll pass on any suggestions.

 

  thanks

[docc]

So, what does the bike actually do? Not start, stall, not restart, stumble, whiffle through the tulgey wood, burble as it comes?

[fotoguzzi]

sidestand switch?

[Kiwi_Roy]

Or ignition switch
They would find it very helpful to monitor the status of the safety circuit with a small lamp at component 57, or Fuse 8 if its wired for an electric petcock.
If the light flickers there's a good chance it's the stand switch as fotoguzzi suggested, my bike showed similar symptoms until I cleaned the ignition switch, the kill switch is also in there

 

 

http://www.thisoldtractor.com/guzzi007/schematics/1999_V11_sport.gif

[-Martin.Glaeser-]

The fuel pump has 2 electric contacts only.

-1-: I'd recommend to monitor those contacts (as proposed by Roy) with a simple 12V lamp indicator.

-2-: if power is interrruped : for interrupted power to the pump, there are more than one reasons:

. one of the relays is broken. Or its socket. Or its wires. ( I will have to check which relay it is )

. controller failure which dis-activates the relay. Caused by several reasons. (e.g. unwanted contact of switches. Unwanted sensor signals)

 

However, I'd like to understand FIRST what led to the diagnosis "fuel pump failure".

Can it not be "spark plug failure" if the bike stalls?

 

-M-

 

[LowRyter]

thanks, I'll pass that on.  I've only seen the bike parked in his repair lot, have never touched it.  He asked me if I had a shop manual for the Greenie, gave him This Old Tractor website, and thought I'd get some advice from the board.

[Tom M]

I had an issue a few years back where my fuel pump was not consistently priming when I turned the key on or cycled the kill switch.  I eventually figured out that I could make it prime every time by moving the wire loom around at the ecu connector.  My ecu was mounted with the connector facing up and apparently the seat base had been flexing and hitting it which eventually cracked an etch in the ecu PC board.  I installed my other TI ecu with the connector facing down and haven't had any problems with the fuel pump since then.

 

If the bike in question has the same symptoms that I had and the ECU is mounted with the connector facing up the mechanic might want to try moving the wires around with the key on to see if that makes the pump prime.  If so it's probably either a wiring or an ECU problem.