Fuel problems 150HP

[mwaller37]

Guys need some help I have aquired a VJ150GLEI Johnson 1991 model engine. I had a tech check all the electronics and all is good. Oil injection has been removed and now is mixed in the tank. The boat sat up for a year or two. I took the fuel pump apart yesterday and the diaphrams aren't cracked but it wont stay running by itself I have to spray fuel into the intake, it acts like its starving for fuel. Anyone got some suggestions?????

 

[tashasdaddy]

Re: Fuel problems 150HP

dirty, varnished carbs. http://forums.iboats.com/showthread.php?t=244013

 

[mwaller37]

Re: Fuel problems 150HP

Thanks for the reply, Going to start that process this afternoon. I think my Fuel pump is pumping because the carb bowls are full after draining and turning the engine over.

 

[ezeke]

Re: Fuel problems 150HP

The fuel pump just fills the float bowls on the carburetors; the fuel is pulled through the carburetor by the vacuum created by the pistons.

When you prime the system with the primer bulb, the float bowls should fill completely, providing enough fuel for starting and several minutes of running.

Your cold starting procedure should include pushing the key in to activate the primer solenoid while you crank and tapping the key in as necessary until the engine warms up.

If you have a warm up lever on your remote, have it up fully for your cold start.

 

[mwaller37]

Re: Fuel problems 150HP

So just because the bowls are full dosent mean the pump is working.

 

[ezeke]

Re: Fuel problems 150HP

There are only three ways that the carburetor bowls can stay full: primer bulb, fuel pump, or gravity.

There is no way that the fuel pump can, in effect, push fuel through the carburetors to the firing chambers unless the float valves are bad. It is unlikely in the extreme that all of the float valves would be bad at the same time.

The primer solenoid allows the fuel to bypass the carburetor and to be injected directly into the intake manifold, then pulled into the firing chambers by the pistons.

 

[mwaller37]

Re: Fuel problems 150HP

10-4 I understand, Thanks for the reply and help. If it will not crank initially it might be a bad primer huh?

 

[tashasdaddy]

Re: Fuel problems 150HP

if the jets are varnished up the cylinders will not get fuel. only thur the primer inlets.

 

[mwaller37]

Re: Fuel problems 150HP

Ok. Going to tall the carbs apart and soak in cleaner tonight, order some rebuild kits and reinstall to try that, I hope its as simple as that!!! Thanks again for your help.

 

[ezeke]

Re: Fuel problems 150HP

Don't soak the plastic parts of those carburetors. Use an aerosol and compressed air.

If you use carburetor kits, your chances of success are much better.

 

[mwaller37]

Re: Fuel problems 150HP

On the schrader valve at the primer soleniod, can you hook up a fuel pressure gauge up there to see if the pump is working?

 

[ezeke]

Re: Fuel problems 150HP

Hook it to the hose from the fuel manifold after the fuel pump. The primer solenoid is just a valve, open or shut, and generates no pressure of its own.

The pulse that runs the fuel pump comes from the movement of the pistons. The correct way to test is to have the gauge in line while the engine is cranked or running. http://www.maxrules.com/graphics/vropics/VROflowchart.JPG

 

[mwaller37]

Re: Fuel problems 150HP

Man were those carbs filthy!, Had to did some of the needles out of the seats and clean the jet out, Got all that done and still no crank. next i'm going to check the other bowl and needle and seat at the primer solenoid to see if its the same way.

 

[mwaller37]

Re: Fuel problems 150HP

When the key is pushed in and on, what causes the primer solenoid to operate? Also shouldnt the chokes operate when the key ion and pushed in?

 

[ezeke]

Re: Fuel problems 150HP

The primer solenoid is just a valve, open or shut; the fuel pressure comes before the primer solenoid, from the primer bulb or the fuel pump.

You don't have chokes on your engine. The primer solenoid allows the fuel to bypass the carburetors and inject directly into the intake manifold; This enriches the fuel/air mix, allowing for a cold start.

 

[mwaller37]

Re: Fuel problems 150HP

Ok. But the little primer solenoid that has wires running to it, it should do something when the key is pushed in right?

 

[ezeke]

Re: Fuel problems 150HP

The solenoid is an electromagnetic device that moves a steel rod in the center of the cylindrical part of the primer solenoid.

When you push in the key, the magnet forces the rod to open the valve and allow fuel to flow through to the intake manifold.

In an earlier response I connected a thumbnail with a section copied directly from a 1988 OMC owner's manual. Except for the momentary ability for the fuel that has been slightly pressurized by the manual primer bulb, the first underlined section is true and applicable for all carbureted OMC motors. That is because without cranking or running, the fuel pump is not working at all and no vacuum is being created by the movement of the pistons to pull fuel through to the firing chambers.

 

[jonesg]

Re: Fuel problems 150HP

Ok. But the little primer solenoid that has wires running to it, it should do something when the key is pushed in right?

when I push my key in, I can hear the primer solenoid click.
Is yours not responding?