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4.3 Volvo penta hard start

cschadow

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I have 2000 Glastron with a 4.3 Volvo Penta engine. It is acarbureted engine so I believe that makes it a GL model. The engine serialnumber is 4012007655.
Hard starting – This issue has been building for a while.
In the past at a cold start, I would pump the throttle acouple of times and it would fire up when I turned the key and keep running.More recently (2018 season), I would have to pump the throttle 3-5 times on acold start to get it to fire when I turn the key and then it would fire andoccasionally quit as if it had no gas. This issue is worse after the boat hasbeen sitting for a week or two. After sitting for a week or two, it is as if Ihave to pump up the fuel from a long ways away. Once it gets there all is good.

Most recently (Memorial Day weekend 2019) on both warmand cold starts, I had to do extensive pumping of the throttle to get it tofire and then it would quit as if it had no gas. Repeat this a couple of timesand it would eventually catch and continue running.

Despite the problem above, the engine, once started, runsgreat. It has consistent performance, power and throttles down withoutquitting. Also if it is restarted just after shut off it fires up again easily.

2 weeks ago, I had the boat in for service to addressthis issue. They diagnosed and replaced distributor cap rotor, plus and wires for$700. Perhaps the engine needed this but did not cure the issue described above.

I would be interested in other ideas before I bring thisto someone else. Ignition was not the issue.
 
I have 2000 Glastron with a 4.3 Volvo Penta engine. It is acarbureted engine so I believe that makes it a GL model. The engine serialnumber is 4012007655.
Hard starting – This issue has been building for a while.
..This issue is worse after the boat hasbeen sitting for a week or two. After sitting for a week or two, it is as if Ihave to pump up the fuel from a long ways away. Once it gets there all is good.

..

I'll pass along a "trick" posted here by Ricardo that solved a similar problem for me on my 2.3L VP. If your 4.3 is carburated as you assume, there should be tubing connections between the carburator(s) fuel bowl and the fuel pump. These are intended to prevent fuel overflow onto the engine in the event of a failure of the fuel bowl float valve. After my VP has sat for a week or more, I experience similar hard starting. Here's what I do: I've rigged a small funnel with a piece of tubing of the proper size to connect to the carburetor port that normally connects to the fuel pump overflow circuit. I then carefully pour gas into the funnel until the bowl is full, indicated by fuel backing up into the funnel. Doing this effectively fills the float bowl. Then, reconnect the original tube and try starting as usual. On my rig, it takes no more that 1-2 start tries and it starts and continues to run. Thanks to Ricardo for this really neat and effective "trick".
 
1. I'll pass along a "trick" posted here by Ricardo that solved a similar problem for me on my 2.3L VP.

2. If your 4.3 is carburated as you assume, there should be tubing connections between the carburator(s) fuel bowl and the fuel pump. These are intended to prevent fuel overflow onto the engine in the event of a failure of the fuel bowl float valve.
After my VP has sat for a week or more, I experience similar hard starting.

3. Here's what I do: I've rigged a small funnel with a piece of tubing of the proper size to connect to the carburetor port that normally connects to the fuel pump overflow circuit. I then carefully pour gas into the funnel until the bowl is full, indicated by fuel backing up into the funnel. Doing this effectively fills the float bowl. Then, reconnect the original tube and try starting as usual. On my rig, it takes no more that 1-2 start tries and it starts and continues to run.

4. Thanks to Ricardo for this really neat and effective "trick".


1.... I would prefer that you NOT quote me out of context, or to say that this trick was passed on by Ricardo (as you have explained).
Perhaps you misunderstood me.

2.... The OP here has a 2000 Glastron with a 4.3 Volvo Penta engine that would be most likely equipped with an electric fuel pump.
If so, there would be NO mechanical fuel pump diaphragm that could burst.
With a diaphragm style mechanical fuel pump, this hose is intended to direct any excess fuel (
caused by a diaphragm rupture within the fuel pump body) up to the primary throttle bores where it will then enter the cylinders.

3..... as noted above, the tube that you speak of (if it is a diaphragm burst protection hose) will dump fuel into the primary throttle bores, not into the carburetor's fuel bowl. The only way for fuel to reach the fuel bowl will be through the fuel inlet connection and/or the fuel bowl vent tube.

4...... What you may have heard me say was:
a..... to save on cranking (engines with mechanical fuel pumps) you can prime a new or empty carburetor through the fuel bowl vent tube prior to initial start-up!
b..... for engines with electric fuel pumps, you can prime a new or dry carburetor by connecting a momentary helm switch to the electric fuel pump's relay.
A few seconds of pump operation (via the momentary switch) will prime the carburetor fuel bowl, and again, will save on cranking during initial start-up.


.




 
Thanks Ricardo for the reply - However, is installing a "momentary helm switch" a fix that a Volvo dealer would install? Or is there a root cause that should be addressed? What would be a reason the carburetor bowl is not priming correctly when it was a year or two ago?

Thanks for your time.
 
..............................
Thanks Ricardo for the reply - However, is installing a "momentary helm switch" a fix that a Volvo dealer would install?
I doubt that you could find a dealer who would be willing to do this for you.

It is very simple.
Install a momentary helm switch (must be momentary in order to not violate USCG regs).
Provide power to this switch.
Run power out from this switch to the triggering side of the fuel pump's relay.
When the switch is activated, it will trigger the relay just as the "start-bi-pass" circuit does during cranking.
The fuel pump will then operate and will deliver fuel to the carburetor.
.... but with NO cranking!

Or is there a root cause that should be addressed?
Typically (if no other issues) evaporation causes the fuel bowl to become dry.

What would be a reason the carburetor bowl is not priming correctly when it was a year or two ago?
If all is working correctly, it will become primed as you crank the engine over.
This is accomplished via the
"start-bi-pass" circuit that triggers the relay during starter motor operation ONLY.

The momentary helm switch simply eliminates the use of the starter motor
"start-bi-pass" circuit.
In other words, you will be able to operate the fuel pump (with the switch) prior to using the starter motor.
In the long run, this can save on starter motor wear and can extend battery life as well.


Thanks for your time.
 
Just some basic stuff after you've eliminated the ignition.
A Holley carb?
Evaporation maybe a sign your engine is heating up now more than previously.
Fuel bowl leaking down? Black smoke / rich smell re-starts may be a sign. After shutdown pull the arrestor take a look down the throttle bores for fuel dripping.
Venting / siphon issue? After a long run, shut down and crack the fuel fill cap to release any vacuum the tank may have built up.
Make sure you're carb pump system is functioning correctly. Should get a decent stream out of the pump shooters when actuated. FWIW, I've had 2300's discharge check valves hang and not get fuel from a full bowl when pumped.
A fuel flow diagram here...…...
http://www.tocmp.com/manuals/Carbs/Holley/H4V-4150-60-80/HolleyB150_html/MCarbHollB150_0008.htm
 
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