How To Test Fuel Pump Assembly?

I removed the fuel pump assembly because the bike acted like it was out of fuel after 3k rpm's.  I posted on this problem earlier and got suggestions that it sounded like a fuel pump problem.  

To outward appearances there is nothing wrong with the pump assembly - all hoses are there in good shape and with original crimped fittings.  Then there is the regulator.

I saw the suggestion to just let the pump run in a bucket of gas and observe.  But will this tell me if the regulator is working correctly?  If the output pressure is adequate?  I have a fuel injected car that experienced low fuel pressure and made it run terribly, even though the pump was still working.

I suppose one could somehow connect a pressure gauge to the fuel pump output?  Has anyone done this?  What should the pressure be?

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This'll probably work. I think the ones the Italians use open at 47psi but I might be wrong. Anyway, close enough......

I tested the fuel pump and with a closed system it put out 45 to 47 PSI. The pump ran as soon as I turned on the bike and then immediately stopped because obviously the fuel injection wasn't hooked up and I wasn't trying to start it just test the fuel pump. I then decided to see what would happen if I slowly opened the closed fuel circuit and found that the pump did not continue to work. That is it had stopped right away with a closed circuit and when I open the circuit it just let the pressure out and did not start pumping again. So I reviewed the earlier post and one suggestion apparently was that I leave it open that is the circuit open and turn on the bike and see if the pump keeps pumping.

So a couple of thoughts have occurred to me. With a closed system, I am not surprised that the pump does not continue to pump. Second question is should the 45 to 47 PSI be present even when fuel is being delivered? In other words should fuel pressure always be at that level regardless of say what RPM the engine is turning?

Another thought is that there must be some sort of safety device on the bike to prevent the fuel pump from continuing to pump when the engine is not running. Anybody know anything about this?

Another question is if there's nothing wrong with the fuel pump then what part of the bike is responsible for spark distribution throughout the engine RPM range? In the old days there was a distributor points and condenser but I guess on this bike it's all electronic? If so what could be the reason that spark would not be available beyond 3000? Actually as I say this I realized that it's not a valid question because I already checked the firing the plugs and saw that they continued to fire even after 3000 RPM's but apparently no gas was getting to the cylinders for them to fire.

Anybody have any insightful ideas that might be helpful to me? I was hoping it was the fuel pump because that's a nice neat little package that can be rather easily addressed.

Pump runs for a few seconds after key on to pressurise the line/rail but will then turn off unless it receives power from the ecu. The ecu won't deliver power unless it sees the motor is running by getting a signal from the phase sensor.

Please forget about points, carburettors etc. they are not relevant.

If it is a sudden cut off like a rev limiter that's very odd. Does the cut off point change depending on how far open the throttle is? Or is it strictly crank speed related?

Pete Roper wrote:

Pump runs for a few seconds after key on to pressurise the line/rail but will then turn off unless it receives power from the ecu. The ecu won't deliver power unless it sees the motor is running by getting a signal from the phase sensor.

Please forget about points, carburettors etc. they are not relevant.

If it is a sudden cut off like a rev limiter that's very odd. Does the cut off point change depending on how far open the throttle is? Or is it strictly crank speed related?

It's like I have run out of gas at 3k rpm's, so I guess it is crank speed.

Do you have Guzzidiag up and running? Or some other form of diagnostic equipment?

Dodgy phase sensor perhaps? Is this a new phenomenon?

Pete Roper wrote:

Do you have Guzzidiag up and running? Or some other form of diagnostic equipment?

Dodgy phase sensor perhaps? Is this a new phenomenon?

I do have goozy diag and I can try to use it. This is a completely new phenomenon. The bike ran flawlessly before and after sitting for a few weeks this problem arose as soon as I was riding it again.

Will it rev over 3K on the sidestand?

Pete Roper wrote:

Will it rev over 3K on the sidestand?

haven't tried that. Never thought about such a thing. However I do believe that the bike runs when it's on the side stand but I'm not positive about that. Would that make a situation where 3000 RPM's would be a shut off fuel somehow? Have checked and the plugs are still firing even after it's dying for fuel starvation reasons I assume

Appreciate your responses I am incapacitated at the moment with a gallbladder problem so I'm just trying to get my research done before I launch into anything. Actually the tank is off and I guess that allows me to look at things that would otherwise be hard to see.

These guys are down the road here, got parts----------------
Saves imports to USA

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Here is probably a foolish question. I do have guzzi diag. I went through the tutorial and still have a question a very fundamental question. Can guzy diag be used to test every electronic component on the engine? I see that there are a lot of electronic devices that affect the throttle and running of the bike. Will goozy diag check these for me? What I read seems to indicate that I choose mostly to reset fuel parameters, would which would not seem to be what my problem is

Have you checked that the fuel line isn't kinked and restricting flow?

If you can hear the pump prime when the ignition is turned on the pump should be working. Regulated pressure should be 47-49 psi.

Guzzidiag, like any other diagnostic software, will give you information on any detected faults of an electronic nature, failed sensors and the like. It won't tell you if a hose has fallen off or got kinked. It's not a magic box. It's simply a diagnostic tool. You are still required to examine the bike for physical faults.

I am not a complete amateur, quite the contrary. What I am looking to know is whether guzy dayag is our can do the same thing as OBD in automotive systems, I. E. Identify items that have faults. There are many electronic additions to the fuel injection electronics aspect of the bike. Many electronic devices. Can each of these items be checked by kuzi D diag and determined to be either functional are nonfunctional

GuzziDiag will show all DTC's. If something generates an error, you can check it.

It can test the fuel pump, injectors, ignition, et al, as well as showing the status of all sensors and switches.

I reviewed the guzzi diag tutorial, the first few pages and it seemed to be addressing changing parameters and maps. I think there are like 30 pages in that tutorial. Do you know right off the bat whether some of those pages address how to access the various components, electronic components that can be affecting are causing the problem I am experiencing? I admit to laziness and asking you this question because to my knowledge you are the person that knows all about this issue and about the tutorial. If the tutorial contains information on how to access these individual components for testing just let me know and I will review it and find the location of the information. Is there a readout on the bike itself on the instrument panels 44 faults? My instrument panel did not show any check engine light or faults. I am grateful for any assistance you may be able to offer and, as stated above, to my knowledge you are the authority on this subject and I appreciate that.

Read the tutorial. If you need clarification on an issue? Ask. You can't expect to be spoon fed everything, sorry, there aren't enough hours in the day.

You can read the error codes from the dash, but it is much easier to connect GuzziDiag and from the menu bar click:

"View" -> "Faults" -> "Read"


To test the fuel pump? Click:

"View" -> "Actors" -> "Fuelpump" -> "Start"

Same with the injectors and ignition. Simples!

beetle wrote:

You can read the error codes from the dash, but it is much easier to connect GuzziDiag and from the menu bar click:

"View" -> "Faults" -> "Read"


To test the fuel pump? Click:

"View" -> "Actors" -> "Fuelpump" -> "Start"

Same with the injectors and ignition. Simples!

Just recovered enough from Covid exhaustion to start to work on the bike again.  What you provided above is exactly what I needed to know.  I can do that.  But a new fact has presented itself:

This is a 2007 US 1100 2v but the diagrams I have seem for the tank appear to make it look like a 1200 4v.  Anyway, there are two (2) hose connections at the rear of the tank which are apparently for gas overflow and such.  They are not a problem.  But I have a third hose that seems to run to the canister at the far end, but I cannot find where it runs to at the near end to the engine components.  My TB's are connected with a hose and have a "t" connection that carries down to below the bike.  All appears intact.

I have read some posts that suggest the tip over valve should be connected to the canister, i.e., that third hose I am stalking about should be connected somehow to the tip over valve.  It certainly is not hooked up that way.  I attach a file showing the 3 hoses.  Note that the mystery one actually is cracked at the connection point and that makes me wonder if that is not the cause of my 3k and it no longer runs problem.  Anyone able to tell me where that mystery line is supposed to connect?  Circled in red

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Tha canister has one hose coming from the tip over valve that is connected to the rear of the fuel tank ,the other smaller diameter hoe goes from the canister to a tee fitting that then goes to the vaccuum fittigs on each thottlebody the same place you would hook up a manometer to . I've removed my canister and joined the vaccuum ports and put a double hose barb in place of the tip over valve ino longer get the pressure buildup in fuel tank and connecting the 2 vac ports eliminated my intermitent high idle fom the crappy stepper motorwithout blocking the stepper hose like some have done with a valve. Hope this helps it did on my 07
2valve GRiSO i did same thing on my 15 when i eliminated the canister

Got this diagram - seems consistent but I still have 3 hoses to sort out.  [You must be registered and logged in to see this image.]

I'm not overly familiar with the canister set up as we don't have it in Oz but one of the hoses in that area will be the gearbox breather hose. It simply vents to atmosphere up under the tank. There is also the stepper feed hose and the crankcase pressure relief hose that plug onto the spigots on the front of the airbox.

On my 07 the drain hoses fom airbox are clear and they get brittle . But if i recall you said one of your hose with the crack went to the canister if its the smaller of the 2 it goes to the throttle bodies . Do you have the vac portrs on tb pluge with a screw or is there a small barb on each with a hose , they are located on inlet tract close to heads 1 on each

This is the small hose and where it goes i used red silicone from space shuttle boosters [You must be registered and logged in to see this image.]

Oh, there is also a drain from the battery tray. That's a thin hose.

And a very small hose from fuel cap