Volvo Penta 4.3 gl just quit in the water!?!???

T2fjdude

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Jun 16, 2018
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36
Folks I really need some advice here. I was out in the bay today, and the boat ran fine for at least an hour... no problem. Then at about 2700 rpm.. it just stopped and I could not get it started. I thought maybe a battery. So, I ran and bought a new battery and nothing. It seems to want to start, but I can't get it to fire up. Please help? Now it sounds like it want to start, but nothing. Its a 2003 4.3 gl-d
 

Augoose

Lieutenant Junior Grade
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Mar 21, 2010
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1,220
Will the engine turn over strong with the ignition key and its just not starting or are you getting a click or grinding when you attempt to turn the ignition key.
Were you anchored in chop perhaps before it last ran?
 

T2fjdude

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Jun 16, 2018
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Its very odd. Its turns over, but it seems like its struggling. I ran out and got a new battery, but still the same. So, I was thinking ignition; I went out and got a new cap and rotor, and a new ignition coil. Still won't fire up. I know I have fuel and spark. I feathered the throttle only, and it sounded like the flex plate was loose or something. I'm beginning to think the engine may have hydrolocked. I'm just baffled. It was running perfectly and then dead in the water. This engine has 10 hours on it. No water in the oil or gas.....Any ideas?
 

T2fjdude

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I will also add that when I turned the engine by hand, it seemed more difficult than before; even with the plugs out. However, the plugs looked clean with no moisture etc. Could I have bent a lifter or something internal?
 

Augoose

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How do you know you have fuel and spark, what steps did you take to check for both?
When you pump the throttle control, are you getting a solid squirt of fuel down the carb? Are you grounding out the plugs and witnessing a good spark jump?
In the video, the battery sounds weak. After you replaced it, does it turn over quicker?
Is the oil level on the dipstick the same as it was before the boat died?
 

T2fjdude

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I checked the know I have fuel because I drained the filter and it filled up when I primed it. I'm fairly certain I have spark because it briefly fires with starter fluid. It did turn over quicker with a new battery, but never ran. Also, I checked the oil many times throughout this issue and it seemed the the same as usual. I did notice a very small amount of water in the fuel from the filter sample, but I doubt it was enough to cause this issue. Also, after it died, I tried to start it winton a minute or so, and it sounded like a weak battery... after 15 minutes it seems to crank and want to start, but wouldn't fire. So, I thought bad battery. Took it and had not tested, and it was in fact bad. New battery didn't help though.
 

wpshog

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Aug 2, 2020
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This sounds exactly like what I am dealing with. I have a 2005 Four Winns Horizon 170 LE with the 4.3 GL. A couple of weeks ago went out two days back to back just fine during the week but Saturday we anchored for about an hour and boat hasn't started since. I replaced battery, fuel pump, fuel filter (primed with fresh gas), tank is full of 93 octane, changed spark plugs today to AC Delco 41-993. I am not seeing anything squirting into the carburetor but kinda at a loss on what to check next.
 

wiigelec

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Jun 22, 2020
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31
What is the full model # of the motor? You’ll have to verify wiring diagram for your full engine # but it should be similar to the following:

Have you verified fuel pump operation by connecting direct to battery? Mine has a green wire on the alternator you disconnect and jumper to b+.

After running fuel pump manually for 30 seconds or so try to fire. If it runs check for 12V where the green wire was connected on the alternator. If no 12V alternator is bad...
 

T2fjdude

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Jun 16, 2018
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Yes. That is very similar to what I am seeing. I am wondering if I am dealing with some kind of internal failure. I wouldn't think the engine would turn if the bottom end was damaged, but without digging into it (which I'd like to avoid) I won't really know. I'm just perplexed as to how it ran fine and just stopped. Though I am new to this, but it is still a gas combustion engine and should operate like any other. Keep me posted on what you find out.
 

T2fjdude

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Wiigelec, from the plate it looks like the model # is 4012142092. I will give your trouble shooting a shot. Do you think it would be worth it to have the alternator tested at a shop? The pump is brand new also, maybe 10 hours on it. Would the engine start with a fully charged battery, but a bad alternator? Thanks for the advice!
 

wiigelec

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Jun 22, 2020
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The engine will start and run as long as there is fuel in the carb bowl and the carb is working properly. There are diodes in the fuel pump relay circuit to prevent backfeeding during start and run that can go bad and prevent the fuel pump from running, as well as the alternator output and fuel pump relay. Find the fuel pump circuit diagram for your engine model to study and understand.

If the fuel pump does not run while green wire is connected to b+ will focus troubleshooting to relay coil circuit.

The key to troubleshooting is to test one thing at a time. Don’t make a soup sandwich by randomly replacing parts. It’s either fuel or spark if it will turn over but not start...
 

wiigelec

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Yeah they are buried in the wiring harness under all that tape. Definitely don’t want to dig for them unless necessary. Fortunately you can test them without tearing anything apart...
 

T2fjdude

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Jun 16, 2018
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Well, I found them and they seem to be in good order, i.e. not burnt. When you said to jumper to b+, did you mean from the wire on the alternator t the positive post on the battery?
 

wiigelec

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Jun 22, 2020
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Just because a diode looks good doesn’t mean it is, you have to check it with the diode function using a multimeter.

Disconnect the wire from the alternator before connecting it to battery positive...
 

T2fjdude

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Jun 16, 2018
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I just had the alternator tested at my local shop, and it had almost no output. So there's that. I'm just unsure why that would kill the engine on the spot. I guess no fuel and a dead battery.
 

T2fjdude

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Jun 16, 2018
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I believe so. He attached the leads to the pins where the cannon plug where the green and purple wires seat; as well as the b+. He ran it on the stand and it was toast. Does this sound correct? Thank you for the patients. I'm definitely a noob at this. Also the diodes are in clear heat shrink. So, I won't be able to put my multimeter on them without cutting them out.
 
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