M620 Fuel Pump Issues

[Vishwacorp]

Left it overnight, went to pick it up and it wouldn't start. After towing it back, it now starts just fine. I'll probably take it back to the dealer since I just got it from them last week but any ideas on what could be happening?

[Vishwacorp]

Anything? The fact that the issue is intermittent is what's annoying! I changed the title of the thread to better reflect the problemooo.

[addiction]

I had the same issue on my 620. I checked everything you did and found nothing. The next day I went to take out the low fuel sensor and found out when I pulled it out the wires the sensor was cracked at the base and the metal "tubes" inside had broken in two. It took almost no force to break it in half. I looked around and found that piece is very expensive and since my Vapor dash cant read the sensor anyway I went to work.

The little "tubes" are the electrical conductors that read the sensor and  run the pump. 2 sets. I just tested with my meter which 2 I needed. I then cut the wires going to the pump, that exit the sensor and cut a little bit of the sheathing off. I then got my soldering iron ready and slip the wires into the holes and soldered them in. Tested the pump and PRESTO it primed. Haven't had a problem since.


BTW My bike sat in my garage for 2 yrs with gas in the tank. (Long story) I think that was the culprit.

[Vishwacorp]

What year was your 620, addiction? Here's my gameplan for this issue. I'm gonna first go talk to the dealer since I did pay that place just last week to "fix" this issue. And depending on the cost, I might diagnose it myself, in which case, I'll probably check the relays and the fuses first then work through the wires since at this point I'm pretty convinced the fuel pump itself is not the issue.

[addiction]

04. I thought it was the pump too but the likelihood of the pump going out is pretty slim. Also run direct power too the pump to see if it works. Thats if its not running.

[Howie]

The fuel sensor is a good possibility, power to the pump goes through the sensor to get to the pump.  A little difficult to nail down in your case though since your problem is intermittent.  Remove it and subject it to vibration with an ohmmeter connected and you might nail the problem.  Or you might get lucky like addiction and see something.

[dark_duc]

Just to throw it out there, we had a similar issue on a buddys 620.  The bike would run sometimes and wouldn't other times.  When it ran, everything checked out fine but when it wouldn't run we found we were getting voltage to the pump so we assumed it was bad.  We replaced it with the ca pump and it still didn't work.  The problem ended up being a loose connection in the wire cluster that passes through the bottom of the module assy.  Even though it is all sealed somehow a loose connection happened.  We scraped away all the sealant, found the bad connector, re-soldered, and re sealed.  Since then no issues.

[Vishwacorp]

That's a very good possibility. I just used a multimeter at the connector under the tank and I'm getting slightly more than 11 volts on both sets of wires. Is that good enough? The lights all work properly and the starter cranks as well. I just don't want to dig up the wire cluster if the final issue is my battery being bad.

Right now, the bike is dead in the streets so I'll take a look at the sensor as well and report back when I'm able to get it home!

[Vishwacorp]

Updates!

Unfortunately, I can't report that the issue has been fixed. When the bike died on me again this past weekend, I decided to diagnose it myself.

Problem - Fuel pump not priming when key in ignition turned to "On"
Step 1 - Check for proper voltage at the connecter under the tank. Both the fuel pump and the low fuel sensor receiving around 12V. Thus, the problem must lie after the connector.
Step 2 - Use SpankyDuc's thread (http://www.ducatimonsterforum.org/index.php?topic=17213.0) to take out the fuel pump/filter assembly.
Step 3 - Check for voltage at the black plug with the red/black wire connected to the fuel pump in the following picture (also from SpankyDuc's thread since I didn't take any of my own photos)


Now here, I expected to not have proper voltage, requiring me to locate a loose connection or something but the pump was getting 12V. I attempted to run it outside the tank for a second (I know I shouldn't run them dry but I figured a second wouldn't hurt) and all I heard was a click, as if it's stuck but wanting to spin.

So my electrics check out, leading me to conclude that it's my fuel pump that has gone bad. But this fuel pump was just put in the bike (with a new filter at the same time) just 3 weeks ago. What could result in a fuel pump dying so quickly?

[Vishwacorp]

And my bike is a 2005 M620 (plastic tank) so I don't think the power to the fuel pump goes through the low fuel sensor.

[Vishwacorp]

So it kept not starting randomly even with the new fuel pump. I replaced the fuel assembly (the whole flange) from another monster and so far it's been working flawlessly. I'll report back if anything goes wrong again :-)