V11 LeMans fuel pump (maybe)

[docc]

And the battery voltage, now?

What type battery is it?

[audiomick]

1 hour ago, docc said:

And the battery voltage, now?

Further to that, what is the difference between the battery voltage measured from battery plus to battery minus directly, and the voltage on plus contact that activates the relay measured from the contact on the relay to battery minus?

 

EDIT: I just went back over the whole thread, and saw that you have posted voltages for both of those at various times, but apparently not for measurements taken at the same time. Relevant is what the battery voltage is when it is not starting (and how much it drops when you try to start), and then how much of that voltage is actually reaching the relay.

 

and then this:

 

1 hour ago, Sporticus said:

 Sometimes the relay will click once, the fuel pump will prime, and the bike fires right up. Other times the new relay will click sporadically (like it did before) for an extended time before the fuel pump primes.

really sounds a lot like an intermittant contact somewhere. I feel that is unlikely to be a faulty relay, and you seemed to have changed all the relays already anyway.

I think you need to look even closer at all the wiring, connectors and switches involved in the starter circuit.

Edited October 20 by audiomick

[docc]

36 minutes ago, audiomick said:

I think you need to look even closer at all the wiring, connectors and switches involved in the starter circuit.

Classic Startus Interuptus?

[audiomick]

Yeah, could be, but intermittent apparently. From what I have read, that is not entirely typical. Having said that, mine starts first hit sometimes, and sometimes it takes several hits on the button. When it doesn't want to start, there is only the one click, not repeated clicks. The thlot pickens...

Edited October 20 by audiomick

[docc]

Later V11 benefit from an additional relay in the start circuit to take the stress off the ignition switch.

[Sporticus]

Checking the voltage right now would be fruitless. I rode the bike to visit a friend, who incidentally owns a relay tester (relay checked out fine). I went to leave after some time. Put key in the on position and waited for the relay to do its prolonged thing before the pump finally primed. Went to start and it just turned over. Turns out I had no spark. Related? I have no idea. Got a ride home and came back with truck and trailer, taking a ride of shame home. Further research will have to wait until I have time to pull the tank and lay eyes on the coil. On another note, the voltage at the relay has always matched that of the battery. Battery is low right now because of prolonged attempts to start the bike.

[Gmc28]

I didn’t read in this thread where you pulled/cleaned the back side of the relay attach receptacle, like Docc advised?  You probably did it, but don’t think I saw that confirmed.  Just spraying deoxit back there isn’t usually adequate, gotta pull the connections, inspect, clean, spray, re-assemble.  Sure sounds like a semi-crappy connection. 

[docc]

4 hours ago, Gmc28 said:

I didn’t read in this thread where you pulled/cleaned the back side of the relay attach receptacle, like Docc advised?  You probably did it, but don’t think I saw that confirmed.  Just spraying deoxit back there isn’t usually adequate, gotta pull the connections, inspect, clean, spray, re-assemble.  Sure sounds like a semi-crappy connection. 

Referring to these hidden connectors under the fuse block?

[Gmc28]

15 hours ago, docc said:

Referring to these hidden connectors under the fuse block?

yessir.  

And good clarification!… thanks, as it’s both back of relay attach and fuse block thats of interest, but only the fuse block has that type of access.  

[Sporticus]

I checked those connections on the back of the fuse box and they weren’t corroded at all. I still sprayed them with Deoxit and reassembled. My bigger problem right now is that there is no spark at either plug. This happened after the fuel pump finally primed (after the relay clicked away for a minute) and the bike still wouldn’t start. I just haven’t had time to remove the tank and investigate. Stay tuned.

[Gmc28]

for what its worth, and other smart/experienced folks may differ, but i’ve never had a no-spark issue be a bad coil.  bad coil connection, or other oddball causes, but never the coil itself on these “middle-aged” italian bikes (MG and Duc).  have seen more than once where a coil is shotgun-replaced due to no-spark, the problem is solved, but then putting the old coil back in resulted in good spark again (so, connections….)

[gstallons]

Can the original poster please give us an update ?

[Sporticus]

1 minute ago, gstallons said:

Can the original poster please give us an update ?

Draining fuel from the otherwise full tank as we speak. During my adventures with the fuel pump relay, the bike stopped producing spark. I need to further investigate the spark issue before going back to the fuel pump issue.

[gstallons]

1 have you checked for B+ at fuse 2 ?

2 does relay 5 click when you turn the ign switch on ? 

3 have you checked for B+ at fuse 1  (some use this fuse and some do not) and fuse 8 ?

 4 does relay 4 click when you turn the ign switch on? 

[Sporticus]

1 hour ago, gstallons said:

1 have you checked for B+ at fuse 2 ?

2 does relay 5 click when you turn the ign switch on ? 

3 have you checked for B+ at fuse 1  (some use this fuse and some do not) and fuse 8 ?

 4 does relay 4 click when you turn the ign switch on? 

THANK YOU!! You just solved the problem with your question about relay four. I hadn’t bothered to replace it (didn’t really know what it did). Relay five, which I replaced, just clicked away many, many times before the pump would prime. I replaced four and the pump immediately primed.