Volvo 4.3 GL running on one bank of 3 cylinders!!??

[James76]

So firstly hello to everyone, as you will see I'm new here.

I just bought my first boat about 5 weeks ago, but due to work commitments the first I had her in the water was on Sunday. It's a 2002, 20ft Caravelle, and I am unsure of the model, but it had a 4.3 GL Volvo inboard. The boat ran great all of Sunday, right up until I pulled back in to the marina. It was quite lumpy, but thought it would settle down. Yesterday I tried starting it again and it was definately running on one bank of 3 cylinders. I swapped spark plugs, leads and cleaned the distributor cap. I checked that I was getting a spark at the 3 cylinders that appeared to be down and I am. I can only now think that it is fuel related. There seemed to be good compression, as much as I never had a compression tester, with the plugs removed there was a good puff coming from each cylinder. I removed the carburettor to check the gasket for foreign objects but all seemed well. I have the carb with me as a friend is excellent with carbs, but I'm unsure if the carb is to blame. I guess I should be checking the fuel pump and filter to see if it's a starvation problem.

I apologise that I don't have the engine number to hand, but I forgot to note it when leaving tha marina last night. I'll hopefully be going back up there this evening to re-fit the carb with new gasket, and hopefully I can pick up a fuel filter today and a vacuum tester for the pump.

Has anyone came across a similar problem where one complete back of cylinders is down? it seems strange to me that it's the whole one side of the V!!!!

Thanks in advance, James.

 

[Bondo]

Re: Volvo 4.3 GL running on one bank of 3 cylinders!!??

I have the carb with me as a friend is excellent with carbs, but I'm unsure if the carb is to blame.

Ayuh,... Get it Rebuilt,.... 1/2 of it is plugged....

 

[2003lsr]

Re: Volvo 4.3 GL running on one bank of 3 cylinders!!??

James, I'm interested in knowing why you think that 3 cylinders are down? If you are getting spark to them, how can you be sure they are not working? Also, is the exhaust manifold on the bank in question getting warm?

 

[James76]

Re: Volvo 4.3 GL running on one bank of 3 cylinders!!??

James, I'm interested in knowing why you think that 3 cylinders are down? If you are getting spark to them, how can you be sure they are not working? Also, is the exhaust manifold on the bank in question getting warm?

Thanks for your reply. The engine is running rough, and when I remove the lead from the distributor cap for any of the 3 cylinders on one bank, nothing changes. And, no, the exhaust manifold is not heating up on one side of the engine! I'm puzzled!!!!

 

[Don S]

Re: Volvo 4.3 GL running on one bank of 3 cylinders!!??

When you pulled the spark plugs out, did you notice any water on the plugs? When you cranked the engine over, did you notice any water coming out of the plug holes? You said the compression "Seemed" ok, what does that mean? Did you do a compression test or just assume it was ok?

 

[James76]

Re: Volvo 4.3 GL running on one bank of 3 cylinders!!??

When you pulled the spark plugs out, did you notice any water on the plugs? When you cranked the engine over, did you notice any water coming out of the plug holes? You said the compression "Seemed" ok, what does that mean? Did you do a compression test or just assume it was ok?

I didn't notice any water on the plugs, nor did I see any water coming out of the plug holes. I say that the compression "seemed" ok as I hadn't banked on the problem I found, so hadn't the appropriate tools to perform a compression test. i just pulled the plugs and there was good "puff" from the plug holes. I know it's not ideal, but at the time the best I could perform! Haha.

I'm hoping to get to the boat again tomorrow and do a proper compression test, and I also plan on checking the fuel pump and fuel filter, or rather replace it. I'm fairly sure it was down to fuel starvation, so should check the basics first I guess!!

 

[Don S]

Re: Volvo 4.3 GL running on one bank of 3 cylinders!!??

i just pulled the plugs and there was good "puff" from the plug holes. I know it's not ideal, but at the time the best I could perform! Haha.

Actually, that means something, you would be surprised how many times people say it "seemed" ok simply because it passed a compression test 2 years ago. It's a forum, you don't know if you don't ask.

You did mention you just cleaned the cap, I would sure replace it and the rotor if over a couple of years old.

By all means replace the fuel filter, but do check the old one for water.

 

[James76]

Re: Volvo 4.3 GL running on one bank of 3 cylinders!!??

Actually, that means something, you would be surprised how many times people say it "seemed" ok simply because it passed a compression test 2 years ago. It's a forum, you don't know if you don't ask.

You did mention you just cleaned the cap, I would sure replace it and the rotor if over a couple of years old.

By all means replace the fuel filter, but do check the old one for water.

I appreciate your comments Don.

I am quite familiar with automotive mechanics, but I'm in a different realm with the marine side of things. I condemned the carb last night until I read some useful info on here about checking the fuel system. The boat had been laid up for a while (how long exactly I don't know!) before I bought it, so there may well have been some water in the tank, or even the fuel filter!! The guy told me it had been serviced recently but the plugs still had the protective paint on them, the same as the block when I changed them!!! Some people!! I guess a real good service including dizzy cap, leads, rotor arm and probably coil wouldn't go a miss!!

Also, and I'm ashamed to admit this, my friend has a garage, and a diesel car had been filled from empty with petrol, and I used the 40 litres that my mate pumped out of the car! I'm now thinking this may not have helped the filtration system. Yes I know, I shouldn't have, but here in the UK, with fuel at ?1.48p per litre ($2.38!!!), it seemed a good idea at the time!! Haha.

 

[Bondo]

Re: Volvo 4.3 GL running on one bank of 3 cylinders!!??

Also, and I'm ashamed to admit this, my friend has a garage, and a diesel car had been filled from empty with petrol, and I used the 40 litres that my mate pumped out of the car! I'm now thinking this may not have helped the filtration system. Yes I know, I shouldn't have, but here in the UK, with fuel at ?1.48p per litre ($2.38!!!), it seemed a good idea at the time!! Haha.

Ayuh,.... That might explain why 1/2 of yer carb is plugged up...

Yer motor has a dual plane intake manifold,...
With 1 side of the carb plugged, the opposite side of the motor see's NO fuel....

It's 'bout the Only way to explain yer described symptoms...

 

[bnicov]

Re: Volvo 4.3 GL running on one bank of 3 cylinders!!??

Rebuild the carb, change out the fuel filter and empty that crap out of the fuel tank. Fuel is expensive, yes, but so are repairs. That fuel is contaminated with diesel. You probably have a good 5-10 litres of diesel along with the crud that builds up in a diesel tank. A fuel tank is never really empty unless pumped out completely. Good luck.