97 volvo penta 4.3 gl multiple problems

[97larson]

I have a 97 Larson with a 4.3 GL. Boat ran fine in spring then started having issues.
1) For some reason at times after shutting the boat off on the water of after sitting on the trailer for a while I lose all power in the boat. trim will not work, radio, starter..Nada. Sometimes after disconnecting the battery and reconnecting power is restored. This is an intermittent problem.Made sure all cables are clean and good and cleaned ground to block.
2) all seemed to be fine yesterday (did all the general checks in the driveway, started it up on muffs, ran fine. Got to the lake, launched boat started right up, On my way back to pick up wife at dock engine started to sputter a little, then just died. Started the boat and would run for 10-15 seconds and then die at idle or half throttle.
3) Pulled the carb last night and there was plenty of fuel in the bowl.
3) I don't know if this is electrical or carb both. I am going to rebuild the carb since it has never had anything done to it in 20+ years..
Any other suggestions as to the intermittent loss of electrical power?
Thanks,
97Larson

 

[alldodge]

Sound good to rebuild the carb, but I think your issue is electrical.

Remove the bat cables from the block and starter post. Clean them up and while doing it look under the insulation at the both ends of the cables. Could be you have some corrosion going on under the jacket. It shouldn't be the main breaker because you said every thing including trim stopped working

If you have a battery switch do the same to those cables

 

[SD2600]

X2 on dodges post.... don’t forget to report back

 

[Lou C]

On the engine there is a large connector (called the cannon plug) that links the engine harness with the rest of the boat wiring. These usually have a spring clamp on them and this can get loose. I’d try to carefully pull this apart and check the connections inside. If they are good then smear a bit of dielectric grease on the rubber mating sections so it slides together well and use a hose clamp to hold it tight.
I had a similar no crank no gauges issue on my old 88 Four Winns a few years back and it was oxidation in the fuse box. Fuse for the ignition sys had continuity but would not pass enough current!
also check the connections on the back of the ignition switch. B=battery, I=Ignition and S=start.

 

[97larson]

Thanks for the feedback.
I did pull the cannon plug. There was some oxidation present. I cleaned as much as possible and applied di-electric grease to plug and secured with clamp. Problem re-occurred so I will start looking at fuses, etc. I did change out starter last night with one I had laying around from a previous mis-diagnosed problem because i don't trust the solenoid on the e-bay starter that was on the boat. Figured it was worth try since I had a good starter laying around. Waiting for the carb rebuild kit to be delivered. I have rebuilt many carter/edelbrock carbs in the past, but never had a vehicle with a Holley. Is there anything specific I need to be aware of with the Holley or any good rebuild guides/videos for the Holley 2bbl carb rebuild. I have looked on-line but only been able to find pertinent info for 4 bbl carbs.
Thanks for all the input

97larson

 

[Lou C]

The Holley 2 bbl is just like the 4 bbl with the secondary part lopped off. No real difference, simple carb to do. Take a look at Holley.com they have a lot of vids, etc. I myself prefer Quadrajets

 

[97larson]

Got the carb done, pretty easy. Only problem I had was the Holley kit had 2 power valves (2.5 and 4.5). The old power valve did not have any markings on it. I did my best guess by lining them up on the workbench and picking the valve that looked the closest to the one I removed, Installed the 2.5 and we will see what happens. now on to the electrical issues.

 

[Lou C]

If you have the specs on the carb (you can find these in a VP shop manual) it will list the way the carb was set up with the power valve and the main jets.

 

[Lou C]

The numbers have to do with at what vacuum level they start to open. Sometimes they use different rated ones on marine engines due to lower vacuum readings with the throttle open much more than automotive engines...

here's an example of their marine 2bbl...

https://www.holley.com/products/mari...arts/0-80402-1

Most of the 2bbls listed on their site, list a 4.5 power valve as what it came with...

 

[97larson]

Guess my scientific method worked. Checked the manual I downloaded years ago to verify and the 4.3 GL model calls for a 2.5 Power Valve.Thanks for suggesting the manual, it sparked my memory that I actually have the manual on a drive, Sometimes I do get lucky.

 

[QBhoy]

Check the cables at the alternator. Good luck.

 

[97larson]

Put carb back on, getting no fuel to carb. Ran diagnostics with voltmeter at relay plug.Diagnostics indicate bad relay. Jumped between terminals 30 and 87 and the pump ran. Kept it energized to see if it would pull fuel to the filter---nothing. Tested terminals 65 and 86 while cranking and got 10.5 volts. Put spare fuel line from pump to a container of fuel and could see the pump pull fuel while jumping 30-87. So I guess there is a problem between the tank and pump also? Guess I will replace relay 1st and then go from there. Cant see having both a tank problem and relay problem at the same time so I will chase the easiest solution 1st --relay.

 

[alldodge]

Might be the antisiphon valve on the tank, over time they can get clogged up

 

[Lou C]

True you can have that problem, you can try running it on an external tank to rule it out.

 

[97larson]

Got the new relay installed it--and nothing.Retested jumping the terminal to engage the pump, the pump runs. repeated all the standard tests as mentioned before and they all check out. The post I am following from Don S from 5-6 years ago states to pull coil wire and ground so engine wont start. Put the red lead for multimeter on 85 terminal and the black on 86. Crank the motor and you should see voltage while cranking. if you do you need a relay and if not there is a bad diode or bad wire. While cranking I am getting voltage, but it is only 1.3 volts. The post does not mention what the voltage should read. At this point I don't know what I have going on--even tried pulling fuel from another container and nothing. So I am pretty sure this is not a tank issue.Leaning toward just replacing the pump at this point. I tried hooking up the fuel pressure gauge and of course got zero on cranking which I figured I would. Don';t want to just throw parts at it until its fixed, Anybody have any ideas? I did get some fuel to carb and could see fuel squirting in carb while working throttle, but only once .Engine will fire if i squirt gas in carb.

 

[alldodge]

Jumped between terminals 30 and 87 and the pump ran. Kept it energized to see if it would pull fuel to the filter---nothing. Tested terminals 85 and 86 while cranking and got 10.5 volts.

Put the red lead for multimeter on 85 terminal and the black on 86. I am getting voltage, but it is only 1.3 volts..

You were getting 10.5V and now only 1.3V
Had fuel in carb but engine won't run, then there was no fuel

You have an electrical problem, something is not making connection

 

[97larson]

I don't believe my original reading of 10.5 was incorrect (may have had the wrong setting on multimeter. I checked setting on meter and have since tested multiple times while cranking. 1.3 volts every time. There is voltage present, just very low. Does anybody know what that voltage reading should be?
I jump the pump and tried to pull directly from gas can, and even though the pump was running it was not pulling fuel. Before I was able to pull gas from a container, I can come to no other conclusion, but replace the pump. All the electrical checks seem to be correct with the exception of not knowing what the reading should be when reading 85-86 while cranking. .

 

[alldodge]

Points 85 and 86 go across the coil of the relay, and 86 goes is ground.

When the motor is cranking 12V should pass thru the Yel/Red wire, thru the diode to pin 85.
When the motor is running 12V comes from the alternator green wire, thru another diode to pin 85.
When ignition is turned to ON but motor is not running, there is no power going to pin 85.

Check your diode

 

[97larson]

I changed out the fuel pump and it fired up and ran no problem, so fuel pump was the problem. Once it fired up I gave it a little gas and it has a definite dead spot in acceleration (done on muffs in the driveway). Carb issue, I think I may need to change the power valve to the 4.5. The chart I obtained during the card rebuild stated 2.5, but that seems a little on the low side and may explain the flat spot. Any other suggestions for the flat spot in acceleration after the carb rebuild besides possible power valve issue?

 

[alldodge]

The flat spot with a Holley carb in most cases is the power valve, it does the transition to higher rpms