Testing kawasaki fuel pump

Discussion in 'Mechanic and Repair' started by ed2hess, Nov 2, 2013.

  1. ed2hess

    ed2hess LawnSite Fanatic
    Posts: 13,083

    On 13hp kawasaki FH381V how would you test whether the pump is getting a good amount of fuel for starting. This unit will only start with starter Fluid. I am running out of reasons why it wouldn't start but runs fine after start.

    Not choke
    Not plugs
    Not carburetor
    Not coils but they are 2 years old
    Not coil gap
    Not valve gap
    Not compression 90psi
    Not leak one side 10% other 30% yes exhaust valve is leaking
     
  2. thom

    thom LawnSite Member
    Posts: 146


    Can you see fuel in the fuel filter while not in use?
    Does fuel remain in the filter while not in use?
     
  3. ed2hess

    ed2hess LawnSite Fanatic
    Posts: 13,083

    Answer to both is yes. I had gas off in picture because I took it to shop to check if key was okay.

    20131102_173402.jpg
     
  4. Jeff in AL

    Jeff in AL LawnSite Senior Member
    from Alabama
    Posts: 727

    Ed,

    Here is fuel pump info from the Service Manual...
     

    Attached Files:

  5. Jeff in AL

    Jeff in AL LawnSite Senior Member
    from Alabama
    Posts: 727


    Ed,

    Another thing you could do to "test" the fuel pump would be to get a small fuel tank and remote mount it above the engine and plumb it directly to the carburetor (gravity feed)... Now if you have ANY fuel supply issues to the carburetor, it can only be carburetor related.

    Have you tested crankcase vacuum?
    If this is a high hour engine, or enough wear in the rings/cylinders, you may not have enough impulse signal being sent at a consistant rate to operate the fuel pump. However, this type of issue is usually only seen or more common on engines at tempeture, not cold.
     
  6. ed2hess

    ed2hess LawnSite Fanatic
    Posts: 13,083

    I probably got the stuff to do that but never done it. The input hoes into the pump was loose earlier in the year and that was causing hard start. I put tie rap and problem went away. This engine is 4 years old with heavy use. It is using oil. Thanks
     
  7. ed2hess

    ed2hess LawnSite Fanatic
    Posts: 13,083

    Jeff,
    Hooked up external gas tank and the machine starts right up on first pull. The fuel pump is pumping fuel into coffee can when unit is running. I tie raped the hose coming into pump to make it air tight won't start from pump.

    20131103_093922.jpg
     
  8. thom

    thom LawnSite Member
    Posts: 146

    It sounds like you have a bad FP, or the vacuum supply to the FP is bad.
     
  9. Jeff in AL

    Jeff in AL LawnSite Senior Member
    from Alabama
    Posts: 727

    Disconnect the line from the "remote" tank at the carburetor and connect back to the input side of the fuel pump... Lower the tank so it is not gravity feed anymore.

    If still starts ok after doing that, I would think you have a restriction either in the main unit tank, valve (if there is one) or the fuel lines?

    If the problem is back, then I would say fuel pump/impulse issue?

    Just a matter of backtracking from a working point going back one step or component at a time to see where the original problem returns.

    Have you checked the impulse line to see if it is cracked?
     
  10. ed2hess

    ed2hess LawnSite Fanatic
    Posts: 13,083

    Yesterday it started 3 times from the external tank today it won't start from that tank. Won't start from fuel pump hooked to the external tank.
    Don't know what changed from yesterday.. Still start with quick start.

    I do know from leak test that exhaust valve on one side has a 30% leak.
     

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