Poor (barely) Running GRiSO 1200 2009

Well, I let my GRiSO sit in the UK for too long.   Tank got ugly.   I replaced the fuel pump with a cheapy from Ebay: [You must be registered and logged in to see this link.]

Then I realized one injector was clogged.   Ruined that injector cleaning it out in the Ultrasonic, coil went Open Circuit.  

Next, I bought a pair of new cheap injectors from China on Ebay.. don't waste your time.. .one sprayed like a garden hose and never shut off the other had a funky pattern.  

So next, I got a pair of used injectors from Pete in Australia and just inserted that pair.  It will idle weakly and then stall, with the throttle wide open the bike will only get to 2000 RPM and then sounds like it lean sputters and just hunts around at 2K, with it wide open in neutral.

I'm wondeirng if the fuel pump I bought and fit (didn't really fit so well, was undersized is the culprit.   The ebay ad says its 43 to 68 PSI but it feels like the pressure may be low to me.. leans out and never revs up.   The spray pattern with injector removed and the bike spinning trying to start looks like a mist.. more than a spray (idle speed).

The spark is strong. Air box and air filter are clean and free of obstruction.

Anybody seen anything like this before?

Puzzled...

It may of rusted out the spring of the pressure relief valve. Needless to say Guzzi won't sell you one but.....

Pressure valve.

There are probably other sources.

Thanks Pete...I thought the pressure regulator was integral to the fuel pump assy and got replaced when I put the new pump in. I don't recall seeing an external regulator ? Wasn't in the tank...didn't see it in the lines ? What am I missing ?

Pretty sure it's in the pump base assembly.



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Yes it is. If you just replaced the pump, not the entire unit the PRV hasn't been changed. Mark's pic shows its location on the mounting plate clearly. It's retained by the two small and exceedingly shitty speed nuts!

Also consider the fuel filter. I had to make a pickup run to retrieve my GRiSO 1100 because I hadn't replaced the fuel filter at 50,000 miles (it had 64,000 at the time).

Funny how well it runs with a new fuel filter.

[quote="Pete Roper"]It may of rusted out the spring of the pressure relief valve. Needless to say Guzzi won't sell you one but.....

Pressure valve.

There are probably other sources.

You guys are spot on. I don't see any corrosion in the PRV but I set the pump up to run on test with a pressure gage on the output of the assembly and there is no real pressure the PRV is just letting the fuel back into the tank.

After removing the PRV.. you can just blow right thru the end that rides in the fuel passage with the O'ring on it and the air goes right thru the diaphragm area. No pressure can build at all.

Thank you! Will procure a new one next.

If the PRV spring has rusted out it is because there is a heap of water in the tank, (Duh! ). The reason for that will be that the gutter drain from around the fuel tank will be blocked.

On the back of the tank there are two nipples inconveniently hidden just in front of the frame crossmember. One of them is the tank vent and will be connected via hose to the charcoal canister, (Or vented to atmosphere in countries that don't use the system.) and the other one, on the left from memory which makes sense as it's on the 'Downhill' side of the filler cap where the water pools.

You need to remove the tank and drain it to make sure all the water is gone and then un-block the drain nipple which has a habit of filling up with calcified shite. Why, when it is really only supposed to drain rainwater I'm not sure? Perhaps it's from water when the bike is washed? But whatever, it is likely to be blocked.

In theory the nipple can be unscrewed from the brass insert moulded into the tank to assist in this process but the reality is usually that it will be seized in good and proper. Because the gallery through the tank to the cap has lots of bends in it you can't just jam a drill through it. (Well you can but you will puncture the tank!) so the way we usually do it is use a small, 2 or 3 mm drill bit which you simply hold and spin with your fingers to clean out the nipple and brass tank fitting and then continue spinning a bit of guitar string or the like in the gallery while periodically blowing from both ends with compressed air.

Eventually you break through the accumulated crud and once there I'd a passage you can flush the whole gallery out from top to bottom with vinegar which, being acidic, will dissolve the calcified shit!

It can be a time consuming and tiresome process but not having a clear drain will eventually lead you to exactly the problem the OP has experienced with his PRV in the tank. Make sure the hose, which will dangle under the bike in the same clip the airbox hoses go through just inboard of the right footpeg, isn't kinked or blocked when you reinstall it on the tank and in future, every few months or at least once a year repeat the vinegar flush and blow out with compressed air to keep it clear.

Michael had to perform the 'Un-constipating' operation on the White Meth Lab's tank this afternoon.

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My PRV in my 09 GRiSO was not working..you can easily blow from the o'ringer sealed port past the diaphragm. I see no corrosion inside...only greenish mung...varnish from old fuel on the spring and diaphragm back or top side. I've ordered a new one but think this one is just fouled...foreign material between diaphragm and its annular seat. Bike was always stored clean and dry inside but the fuel went off...I changed out the fuel pump
..so warming to others ...clear all passages and check pressure after fuel pump and filter renewal...system got contaminated and fouled.

I installed one of these :
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3.5 bar PRV with pipe.   Works great now.

Fuel line leaking .. drip drip drip where I heated it up to stupidly remove from injector before I figured out it was just pushed on with an O'ring a little further down..

Anyone have a fix for this ?   A hose clamp hasn't done the job ..

Thanks!

Nope. New fuel line required.


Let this be a warning to others: Never heat up your fuel line.

Hmm.. looks like the fuel line assy has been discontinued. Odd.. not even a used one hanging about in the shops here..

Would like to have a factory setup.. but may have to plumb with rubber based lines.

Many GRiSO parts are now made from unobtainium. I think aftermarket fuel hose will be the only option.

I haven't found the ends that go on the injectors as a separate part but the end that goes on the spigot is readily available.

I'm pretty certain I've got a factory hose lying about. I can look if you'd like?

Pete...not sure I read you correctly. Is an assembled octopus...Quick disconnect goes on fuel pump spigot then plates line cramped to tee that branches to each side then cramped on injector mount..

Mine leaks on the injector mount or carrier.

You have the whole assy ?

Thanks
Danny

Have you replaced the injector seals?

Yes, Pete, new O'rings on the injectors all around.

I rogered the end of the fuel line by overheating it. The plastic end appears to be porous now where it goes over the nipple on the fuel injector carrier..

Hard to find original parts for this .. don't really like to improvise but may be necessary.

Thanks guys! All came good in the end.. just got a hose clamp in the right spot to defeat the drip.

Appreciate the help and the parts shipped, thanks Pete and Bettle and all the rest !