fuel filter?

[guzzi1]

have a starting issue.to much cranking until bike starts.pulled tank off to change $66!!! filter only to discover my bike doesn't have one.i have a factory manual and my fuel system is totally different.no external fuel pump either.i'm guessing internal in the tank.is there a schematic for this i don't have to pay for?my bike is a v11 lemans with calfornia emission on it.2003 but i do have the famous bubbly engine paint.no pad on top of fuel tank.i have very limited shop support but a well equpped garage with a lot of guzzi love and patience.oh,and if i turn the key on and cycle the fuel pump 3-4 time it's like i primed the pump and the bike will start almost immediately instead of 4-5 seconds of aimless cranking.thanx for your help in advnce,daveg.

[raz]

Searching this forum you'll find some pictures and facts about internal pump/filter.

 

The sympthoms I have seen when fuel filter is clogged is you can start it, good idle, no problems at low speed but fuel starvation when trying to go faster. Impossible to overtake a car etc etc.

 

Do you have any problems once it is running? If not I guess the fuel filter is fine.

[gstallons]

When you consider how critical fuel pressure and volume are you will understand why you are going to replace the filter. The filter is in the tank on the fuel pump module. I don'tknow if the filter is the same part # for internal or external part.

I would change this every other year and cut the old filter in half and examine the filter media to justify why you are doing this.

[guzzi1]

Searching this forum you'll find some pictures and facts about internal pump/filter.

 

The sympthoms I have seen when fuel filter is clogged is you can start it, good idle, no problems at low speed but fuel starvation when trying to go faster. Impossible to overtake a car etc etc.

 

Do you have any problems once it is running? If not I guess the fuel filter is fine.

no problem when running jst needs extra cranking to start.if i cycle the pump by turning the key on and off 3-4 time it helps.is my pump going bad maybe?the bike has 13665 on the odo and that is not all that much.as stated before i have little or no dealer support.and the factory manual i bought new when i got the bike is outdated apparently.i guess they revised the fuel system in 03.is there a check valve that holds fuel pressure in the system when the bike is turned off or does it reprime the pressure when you turn the key on.it act like all the fuel runs back to the tank when it sits and then has to pump itself back up.hope i'm explaining this in a way that makes sense.thanx for your input.daveg

[raz]

As soon as you start cranking the pump goes on again. A friend of mine had lots of problem with his Duc 916 in-tank pump and filter. Something leaked so he lost pressure, but since it leaked internal to the tank there was not much evidence of it. It ended up being a weak clamp. But his problems was mostly on WOT.

 

Maybe it's not fueling. You might want to check your spark plugs, as well as battery voltage (preferably when cranking).

[guzzi1]

As soon as you start cranking the pump goes on again. A friend of mine had lots of problem with his Duc 916 in-tank pump and filter. Something leaked so he lost pressure, but since it leaked internal to the tank there was not much evidence of it. It ended up being a weak clamp. But his problems was mostly on WOT.

 

Maybe it's not fueling. You might want to check your spark plugs, as well as battery voltage (preferably when cranking).

put new plugs in today even though plugs in it were pretty fresh.they looked fine.double checked valve adjustment and it was good.cranks over fine and battery is fresh.i just don't get it. i could take the pump out of the tank but then what?when it's running it runs great.it's just getting it to start normally.

[raz]

i could take the pump out of the tank but then what?when it's running it runs great.it's just getting it to start normally.

That is the problem with those. My friend had intermittent problem for months before he nailed it down. He replaced the filter and some hoses that looked marginal. He tried looking into the tank through the cap when running, looking for swirls or bubbles. He disassembled the lot several times and just visually checked hoses and stuff. He listened carefully to the various sounds when priming and when the priming ended. He didn't catch that failing clamp because it was fairly tight, but there is quite a pressure in the fuel system and apparently it was leaking good. And it was temperature dependant too.

 

What you can do to confirm a problem is measure your fuel pressure down at the injectors. When priming you should have 3 bar, when priming stops you should still have at least 2.5 bar for several minutes.

[fotoguzzi]

good point on loss of pressure thru leaky clamp// But have you tried starting w/throttle open 1/4 turn? I have to give throttle for a quick start.

[guzzi1]

after disassembling the pump as far as i could and putting it back together,unplugging and replugging multiple electrical connections,resetting the valves to the tight side of the tolerance,and generally going over everything related to the wiring harness i found nothing overtly wrong.however.....the bike now starts right up.i did nothing in a very scientific manner but apparently touched the right spot in the right way and cured the problem at least temporarily.if i find the exact cause i will post it here for you guys,thank you for your input and i'll be back here soon.

[savagehenry]

...resetting the valves to the tight side of the tolerance...:

For ease in starting, and increased torque exactly where you use it on the road, set your valves on the looser side. Try intakes at .008" and exhausts at .010". The manuals valve specs are not the best settings in real world applications, like traffic. It's one simple adjustment that can make a noticable difference as soon as you hit the road.......Good Luck,S.H.