1999 Volvo penta 4.3 shutting off after 15 minutes of under load

[Bob Tankersley]

The recurring similarity of reported events of loosing engine power on Volvo Pinta boats after normal operation for 10 to 20 minutes could be correlated to the absence of adequate venting of the fuel tank. The symptom of engine running normally for a short time and subsequently stumbles and dying fundamentally indicates fuel starvation.
As fuel is drawn from the tank the volume (space) above the liquid is increased and without venting, the static air pressure is proportionally lowered, forming a partial vacuum. The fuel tank must be vented in order to maintain normal atmospheric pressure on the liquid surface. The reported symptoms reflect a pattern of engine restart and run normally after a short interval supports this hypothesis ,because the time interval has allowed limited venting to restore atmospheric pressure and allow the low pressure (lift) pump bring fuel up from the tank.
The fuel filler cap is the only route to vent atmospheric pressure into the tank, which cap it has an internal plastic “SURGE PLUG” that is intended to prevent fuel from spilling out on the side of the boat when making sharp turns. The surge plug can become wedged in the cap and remain closed, preventing air from freely entering the fuel tank. The reported varying time intervals between stalling events is explained based on the fuel level in the tank. The time interval between the stall is predicated on the fuel level at the time. The time interval would be shortened when the fuel was almost full, because the air space above the liquid would be small and without adequate venting a partial vacuum would form sooner than if the tank was nearer empty

 

[Bob Tankersley]

The Volvo Pinta engineer(s) that designed the fuel pump for the 1980/1999 evidently were trained during the carburetor era and were just then learning the principles of fuel injection. It just doesn’t make any sense to have a low and high pressure pump and even less logic to include a needle /seat and a float. Carburetors use a float to maintain the fuel level in the bowl to meter the fuel into the low pressure created by the air velocity through a venture .Throttle body and port injection does not utilize a venture or float bowl. Nonetheless, there is a plastic float and needle/seat in a chamber of the Volvo Pinta fuel pump assembly.
The fuel injectors are cycled on/off (duty cycle) from an electronic control module and the fuel pressure remains essentially constant during all power modes .The duty cycle (pulse duration) of the injectors regulates the amount of fuel delivered into the combustion chambers. The Volvo Pinta engineers evidently didn’t think that the General Motors engineers were very intelligent by allowing the excess fuel pressure to simply freely flow back into the fuel tank. Therefore, they fell back on their vast experience with carburetors and added a float bowl and a low pressure pump, which design has been causing a myriad of problems ever since. The best “fix” of the poorly designed system is the scrap it entirely and install a single inline high pressure (50 psi) pump between the fuel tank and throttle body or fuel rail and a return line from the pressure regulator to a “T” fitting in the line between the new pump intake and the fuel tank. Problem solved! The new pump must be rated higher than the stated pressure of the injector system since the pressure regulator will maintain the correct pressure at the injectors’ and allow the excess fuel to flow back into the tank

 

[dypcdiver]

Bob, He said he has no spark. However you do have a valid point.

 

[Bob Tankersley]

The Volvo Pinta fuel pump has an unfortunate design flaw that is equipped with a low and high pressure pump and with a float/needle &seat like a carburetor. Initially it worked OK, but after several years the plastic float would become saturated with gasoline and exhibit less buoyancy. With age, essentially all of the Volvo Pinta fuel pumps start showing engine running problems and the cause is centered with the float, needle& seat. The Volvo engineers evidently believed they were smarter than the General Motors engineers, who had originally designed the throttle body and port fuel injection systems. The Volvo Pinta engines are in fact is re-branded General Motors engines. That Volvo engine is a Chevrolet, which needs only one high pressure pump, a pressure regulator and a return line to deliver the excess pressure back into the tank. Auspiciously, there is a “FIX” for that problem and without spending a small fortune on another pump. The pump is held together with Torx head screws and it comes apart easily. You will find a float, needle/seat in the pump. You can just rip the whole thing out and pitch it in the trash. With the seat removed there is a hole remaining in the top of the housing. Locate a 0.332” (letter size Q) drill. Drill that hole all the way through the housing. Locate a 1/8 -27 NPT tap and thread the fresh hole about two thirds of the thickness of the housing. Be carefully and go slowly with the tap and use some transmission fluid (or similar oil). Progressively, turn the tap about one half a turn and back it out a quarter turn and continue that sequence until the correct thread depth is achieved. If you run that pipe tap straight through without backing out every half turn, you will destroy the aluminum part. Wash every speck of aluminum shavings’ off from everything. Reassemble the pump while applying petroleum jelly or transmission fluid to all of the O rings.
Go online to Amazon.com. And order these items:

https://www.amazon.com/Metalwork-St...eaded+nipple&qid=1558235203&s=gateway&sr=8-94



https://www.amazon.com/Brass-Hose-B.../4+barbed+Tee&qid=1558235374&s=gateway&sr=8-4


https://www.amazon.com/Koehler-Ente...gateway&sprefix=1/4+fuel+hose,aps,156&sr=8-17
------------------------------------------------------------------------------------------------------------------------------------------

https://www.amazon.com/Raider-Polyu...gateway&sprefix=1/4+fuel+hose,aps,156&sr=8-23
Put a short section of the 1/4 “ inch fuel hose on the inlet barb of the pump (by the filter) and install the brass Tee in the other end of that hose. Connect the fuel hose from the tank on the other end of the Tee. Connect another section of the ¼ inch fuel to the remaining barb of the Tee and connect that hose to the barb fitting (you have just installed) on top of the fuel pump. And don’t forget to tighten the clamps on all hose ends.
Now you have essentially what the old Chevrolet car/ pickup had, which worked perfectly for over 50 years. The high pressure pump and the pressure regulator will maintain the correct pressure at the injectors and the excess pressure will freely return to the tank. Don’t forget to plug the little rubber hose that was originally connected on the top of the fuel pump.
Good Boating to you

 

[Bob Tankersley]

If you are losing spark and can’t locate the problem after digging through manual, miles of wires the over- completed relays, there is a simple and inexpensive solution. Get rid of the distributor and ignition coil and install a new HEI distributor, which needs only one wire from the ignition switch to provide 60,000 volts to fire the spark plugs. The tachometer can also be connected with one wire to the HEI distributor
Go to Amazon.com

https://www.amazon.com/gp/product/B076DXBHQC/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

 

[Bondo]

If you are losing spark and can’t locate the problem after digging through manual, miles of wires the over- completed relays, there is a simple and inexpensive solution. Get rid of the distributor and ignition coil and install a new HEI distributor, which needs only one wire from the ignition switch to provide 60,000 volts to fire the spark plugs. The tachometer can also be connected with one wire to the HEI distributor
Go to Amazon.com

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Ayuh,...... That is not a marine rated distributor,.....

Between this, 'n yer other "work-arounds", yer building a Bomb,.....

Your "advice" has the potential to kill fellow boaters,......

 

[alldodge]

Agree, your building a bomb

Your taking the reservoir (VST) which would not be under pressure and pressurizing by the low pressure pump. Then your adding non-USCG approved fuel line and running it back to the tank. Fuel line shall be type A1 not Poly

https://www.amazon.com/Raider-Polyu...gateway&sprefix=1/4+fuel+hose,aps,156&sr=8-23

 

[Scott Danforth]

If you are losing spark and can’t locate the problem after digging through manual, miles of wires the over- completed relays, there is a simple and inexpensive solution. Get rid of the distributor and ignition coil and install a new HEI distributor, which needs only one wire from the ignition switch to provide 60,000 volts to fire the spark plugs. The tachometer can also be connected with one wire to the HEI distributor
Go to Amazon.com

https://www.amazon.com/gp/product/B076DXBHQC/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

HEI has no place in a boat. it makes a perfect trigger for a bomb.

it also will not work with EFI.

 

[Scott Danforth]

Crazychris1999 did you replace the diode? or at least bypass it for testing?

 

[muc]

I’m thinking we got 2 TROLLS. What do you think?

 

[QBhoy]

Does it turn over after it dies ?

 

[Bondo]

I’m thinking we got 2 TROLLS. What do you think?

Ayuh,..... Bad Info, no doubt,.....