First post! Volvo 4.3gl woes

[larson176]

Hi everyone its first post time! Any help would be appreciated

my 4.3 gl has got issues! its year 2000 carb version
I bought my Larson a few months back off a friend who didn't use it for a season so i knew it would need going through!

The fault.
Engine cranks from cold fires up and runs sweet for about 3mins then dies with little warning try to start again it fires but but soon stops 1-2 seconds. If I leave the engine for 30 mins or so it starts up again and the whole cycle continues as before.
So far i have replaced coil,dist.cap rotor arm, kill switch, ignition switch removed cleaned/checked carb inspected and replaced fuel filter for water etc, ive played with the electric coke makes no difference. The engines getting plenty of fuel had plugs out.

My only thought is its either a wiring issue bad earth maybe or the pick up coil in distributer.
If anyone has had the same problem or has an idea of the fault i would be very grateful
Thanks in advance
Andy

 

[Bondo]

Re: First post! Volvo 4.3gl woes

Ayuh,... Welcome Aboard,...

I guess the 1st place I'd look would be,...
Right when it Quits running,...

Is it lacking Fuel, or Fire,..??..??

My 1st Guess is Fuel,.. But you're there,+ see it as Electrical,...

Checking when it Dies should reveal the Right Answer....

 

[Don S]

Re: First post! Volvo 4.3gl woes

It sounds more like a fuel/choke/idle problem to me. Once you start it, do you give it any throttle at all or just let it idle?
Being a carbed engine, after a couple of minutes the choke may still be shut and if you aren't giving it any throttle, it's probably just flooding out.
After 30 minutes, it again needs that extra fuel.
Could also be carb ice. Depending on your temps this time of year.

 

[larson176]

Re: First post! Volvo 4.3gl woes

Thanks guys for help
The plugs are wet after it stops i have run the engine at idle and at higher rpm and it still dies. when it goes to stop ive pumped the throttle and it doesn't do any thing still dies. The accelerator pump works fine on the carb.
Once its stopped and wont start up again it will run on the starter if that makes sense until you release the key and it stops dead again. Weird!
Ive spent all day messing with it! all good fun!

 

[Don S]

Re: First post! Volvo 4.3gl woes

Hang in there for a bit, I have to get some diagrams together for you to do a couple of tests.

 

[larson176]

Re: First post! Volvo 4.3gl woes

thanks don youre a gent!

 

[Don S]

Re: First post! Volvo 4.3gl woes

Hre is a wiring diagram of your fuel pump circuit. What it sounds like to me is that while you have the key in the start position with the starter engaged, the electric fuel pump is getting power from the start relay and going thru the diode which energises the relay on terminal 85 (from the orange wire) and keeps the fuel pump running.
When you let off the key, the engine should be running which puts power to the same relay 85 terminal but the power is coming from the green wire and the diode that comes from the alternator.

Now, lets do some testing.

Remove the FUEL PUMP relay from the socket. It's located just above the fuel filter and next to the pump. Go by wire colors, the start relay is there also.
With the key off, put a jumper between terminals 87 and 30 shown by the blue wire below.

When you turn the ign. key back on to the RUN position, (not start position) the pump should run. You probably have never heard it before because it doesn't run unless the engine is running or the starter is turning the engine.

OK, the pump should be running. Now, start the engine and see if it keeps running. If it does, With a Volt meter, check for power between the 85 terminal (Green wire) and the black wire (term. 87) you should see battery voltage. If not, check with your meter on the green wire on the back of the alternator and ground. You should see battery voltage.

Shut off the engine and REMOVE THE JUMPER WIRE.

Report back with your findings.

 

[larson176]

Re: First post! Volvo 4.3gl woes

brilliant, Don give me a few days i will keep you posted thanks a millon!

 

[larson176]

Re: First post! Volvo 4.3gl woes

Hi Guys,
Still waiting for some time off to get stuck into it on thinking about it im not sure the altenator is working correctly does anyone have a wireing diagram for the altenator it seams a bit over complex for marine application! i presume its left over from automotive application.
Has anyone done a moddified fit to incorporate single pole Altenator to get rid of all those damn relays etc!?

Thanks in advance

 

[Maclin]

Re: First post! Volvo 4.3gl woes

Just a thought, firing up while cranking then dying as soon as the key returns to ON is a symptom of a problem in the coil's ballast resistance circuit. The ballast circuit is bypassed during cranking so the coil gets the full 12v. Could be loose or cracked/degraded wire, or bad connections at the coil or anywhere in the circuit really. And it could be a combination of malfunctioning pickup coil and bad wiring, the fuel pump circuit also has a bypass that gives the fuel pump power while cranking, and when just ON it has to go thru an oil pressure safety switch. The symptoms sound like more than one problem to me. Sounds like help is on the way!

 

[Maclin]

Re: First post! Volvo 4.3gl woes

Sorry for the redundant info on the fuel, somehow I scrolled right past Don's diagram post. You are in the right place that's for sure!

 

[larson176]

Re: First post! Volvo 4.3gl woes

Good News i did the test as Don recommended on the fuel pump relay it now runs beautifully !!!!!!!!
I presume its just a case of changing that duff relay? my alternator now charges now too! Is this a common fault on the Volvo Penta?

None the less, Don if you are ever in Plymouth England ill buy you a beer or two or three!!!
So very grateful for the advise everybody!
Regards Andy

 

[Don S]

Re: First post! Volvo 4.3gl woes

I gave you a bunch of tests, what checked out wrong, does it work with the jumper wire in? Did you test to find out if the relay was bad or power wasn't getting to it or what.
What did you find wrong with your alternator?

 

[larson176]

Re: First post! Volvo 4.3gl woes

Hi yep it worked with the jumper in the alternator also started working, don't know if thats linked or not

 

[Don S]

Re: First post! Volvo 4.3gl woes

If the alternator is now working, put the relay back in and see if it starts and keeps running.