5 Volvo 4.3L GL-A Fuel Pump Problem When Starting

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bruceb58

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Could be something as simple as your carb accel pump pump not squirting fuel. Do you pump your throttle a couple times before you start? Look inside the carb throat and see if you gets small jets of fuel when you pump the throttle.
 

VolvoBoater

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I have a 2005 Volvo 4.3 GL-A engine that has a starting problem. If I turn the key the engine will turn, but it won't start. It doesn't appear to be getting any fuel.

Diagnostics
I pulled the green wire (L post) on the alternator and jumpered it. The pump sounds like it's running, so I think that much is OK. Because the fuel relay is also switching properly when I did this (pump runs) I think that's OK too.

Because there are diodes involved that can potentially go bad I also tested the wire from the alternator. I used a VOM set to ohms and put the hot lead at the alternator side and the negative probe in the 85 connector of the fuel pump relay socket. It shows low resistance when current flows from the alternator to relay. I reversed the probes and it shows resistance at 1.0 (no current flow), so the wire and diode are OK.

In reading several other posts on similar problems I learned that while starting, the pump gets power from the starting relay. On my engine this is located in the electronics box attached to the starboard riser. I tested the yellow/red wire coming from the 85 pin the same way I did the alternator (green) wire. It shows low resistance from the starter relay to the fuel pump relay and 1.0 on the reverse, so it's also good.

I pulled the fuel filter off and poured its contents into a jar to check for water and sediment. It's clean, and the filter is new, so I doubt there is an issue there. The Holly 2bbl carb was just rebuilt and when I tested the engine (before putting it in the boat) it started and ran great, so there shouldn't be any issues there.

I checked the kill switch and it looks like it's good (lanyard clip is attached with the spring loaded pin depressed)

Just for grins I pulled the fuel supply hose and put an outboard priming ball and a section of clear hose on so I could see what was happening. I also checked all connections in the fuel system from the carb to the tank to be certain there are no air leaks.

If I prime the system using the priming ball, I can start the engine and if I play with the throttle a bit I can keep it running. Once the engine has been started and runs for a minute or two I can shut it down and restart it without doing anything else. Although this works, I don't really want to have to open up the engine compartment every time I need to start the engine.

I've run out of stuff to try and it has me really frustrated. The pump runs when it gets power, so the pump is good. The wires (and diodes) from the starter relay and alternator are also good (if my test was valid). The fuel pump relay seems good since it runs the pump when it gets power from the alternator (I didn't test power from the starter relay).

What else is there to test? Any ideas for things I might have missed would be appreciated.
 

muc

"Retired" Association of Marine Technicians...
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It's possible the check valve in the pump is bad and allows the pump to drain back.
 

skydiveD30571

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What's your starting procedure, both cold and warm? Not very many VP carbed boat engines are just "turn the key and start".
 

VolvoBoater

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Bruceb58 - Thanks for the suggestion, I looked, but don't see (or smell) any fuel being squirted when the throttle is pumped (neutral to full forward and back.) I'm looking down the barrel or the carb and see a couple of venturi rings, but no jets. Should this be easily seen?

Muc - If the check valve is bad would the fuel leak back to the tank with the motor stopped? When I had the clear line and primer ball connected, I saw no leak down with the engine off.

SkydiveD30571 - I'm new to the boat, so I followed the procedure in the boat owners manual.
Operate blower and Attach Emergency Stop Switch lanyard to its switch and operator.
Cold Start
1. Ignition switch off
2. Move shift/throttle to full throttle.
3. Repeat if necessary,
4. Place shift/throttle in neutral.
5. Turn ignition key clockwise to start position and hold (not more than 10 seconds)
6. As soon as engine starts, release key to run position.

Warm Start
Same as above, but skips steps 2-3
 

bruceb58

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When I first bought my boat, I had starting issues when cold, I had to take the carb apart and clean out the accel pump jets too.

You need to push the button in your control to allow you to advance throttle without being in gear. Pump a couple of times and start with the throttle open a bit. Sounds like you are bringing the throttle all the way back which is going to be an issue. You need the throttle open a little bit when you start. Just keep your hand on it while you are starting so that you can bring back the idle so you don't over rev the engine.
 

skydiveD30571

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What Bruce said, which is why I asked.

Try this on for size next time:

Using the throttle-only button on the control, go to full throttle once (may need a couple shots depending on how it goes), then back to about 1/4 throttle.
Turn key
When it catches, release key and adjust throttle for about 1500rpm to allow engine to warm up

For warm starts, same thing except don't go to full throttle first. Just crack the throttle open and crank, then adjust for rpm's. You'll have to learn her personality and what works best for her.

I spent an entire year chasing around carb problems for symptoms like yours when it turned out to be me incorrectly starting it up. Not saying there isn't some underlining issue somewhere, but start with the easy fixes first :)

I asked about warm starts a while back and got some good answers:

http://forums.iboats.com/forum/engi...oards/590366-why-do-warm-starts-need-throttle
 

VolvoBoater

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Thanks for all the info and help. I really appreciate your suggestions. Because I didn't see any gas squirting in the carb before when the throttle was pumped, I tried jumpering the fuel pump to prime the system. I let it run for about 15 secs and then pushed the throttle forward to full and back a couple of times. When I watched for fuel squirting in the carb I still saw nothing, so I'm thinking there may be an issue with the pump not drawing enough pressure to prime the system (Muc suggested it might be a stuck check valve.) Fortunately, I've got a couple of spare pumps in my shop, so I'm going to give a different pump a try tomorrow. I'm also going to temporarily install a short piece of clear tubing so I can see if the pump is pulling up fuel from the tank. Is there a good way to bench test a Volvo fuel pump to verify it's working properly or would I need vacuum gauges? The Selloc manual I got is not very detailed on testing and troubleshooting.
 

bruceb58

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You can verify the pump with a pressure gauge. The fact that your engine runs fine once it's started indicates it's not your pump.

Throw away the Seloc and get an OEM manual. What is your model number?
 

kelleyja

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The fact that your engine runs fine once it's started indicates it's not your pump.

+1 on this. An easy way to see if the carb has gas in it is to remove a lower float bowl bolt. If there's gas in there, it will drain out the bolt hole. If there's gas in the bowl and no squirts from your accelerator pump when you pump the throttle, then you've found your problem.
 

Crime Donkey

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Was there ever a resolution to this problem? I have similar issues as VolvoBoater. I have an 2003 4.3L GL-C. I've replaced spark plugs, plug wires, cap/rotor, ignition control module, coil, fuel pump, rebuilt the carburetor, insulated the fuel line, replaced relays and checked fuses. Issue occurs after cruising, we stop for a while to swim. The engine won't start after sitting. Sometimes, if it does start, it dies after about 30 seconds (probably running fuel out of carb). Any suggestions would be great!
 

Crime Donkey

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Jul 16, 2023
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Was there ever a resolution to this problem? I have similar issues as VolvoBoater. I have an 2003 4.3L GL-C. I've replaced spark plugs, plug wires, cap/rotor, ignition control module, coil, fuel pump, rebuilt the carburetor, insulated the fuel line, replaced relays and checked fuses. Issue occurs after cruising, we stop for a while to swim. The engine won't start after sitting. Sometimes, if it does start, it dies after about 30 seconds (probably running fuel out of carb). Any suggestions would be great!
Oh, and I replaced the ignition switch and checked the lanyard kill switch.
 

Natman1961

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Aug 4, 2023
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I am also having a similar issue. I replaced the Gimbal bearing and went to test. Put it in the water, started and ran almost 2 minutes and then boat died. It would not restart. Took it home and put the muffs on and started for about 5 seconds and died!!!

MODERATOR EDIT: This thread is from 9 years ago . . . best to let it rest.
 
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