Fuel Tank clog

[Jack2048]

Hey all,

I have a 1994 Volvo Penta 5.0 Fi. Started it up for the first time today ( I know, a late start for the season ) and ran great for the first few minutes, then quit.

Engine has been running great, I have done a lot of work, cleaned injectors, fuel line, new fuel line, about two or three seasons ago. New fuel filter last season.
I had the fuel tank emptied and cleaned about three years ago.

I could hear the whine of the fuel pump, so I knew it was a fuel starvation issue. Pulled the fuel line and there seems to be something clogging the pickup inside the tank. Fuel is not flowing out the fuel line. When I blow on it, I can hear it bubble inside the tank, then gas will flow, but clogs again.

Looking at the picture, is it possible to disassemble this? Can I undo the thread holding the elbow onto the tank so I can pull the pickup tube and clear it up?



Also, when I put the cover back on just now, I noticed the fuel filler cover / cap was not sealed. Must have been like that the whole winter.

Not sure how to proceed.

Thoughts?

 

[mklearl]

You should be able to unscrew that elbow and pull the pickup tube. I'd be more concerned with the cap being left unsealed all winter. Cleaning the tank 3 years ago doesn't do you any good if precipitation was allowed to get in the tank for the last 6 months. Change the fuel/water separator filter and run off an external tank. If it runs fine then the problem is in the tank. If not then perhaps the pump is shot.

 

[Jack2048]

>You should be able to unscrew that elbow and pull the pickup tube.

Ok, good, I will do that. I wasn't sure what would happen and don't want to create a bigger problem.

>I'd be more concerned with the cap being left unsealed all winter.

>Cleaning the tank 3 years ago doesn't do you any good if precipitation was allowed to get in the tank for the last 6 months.

Well, I do keep it covered, so I don't think there is a direct precipitation issue, more of an issue would be condensation.

>Change the fuel/water separator filter and run off an external tank. If it runs fine then the problem is in the tank.

Well, the problem is that when the engine quite, I checked the pump, then pulled the fuel line and dropped it below level of the tank and fuel did not pour out. Blew on it to clear it, then fuel came out. Hooked it back up, engine ran for a bit, but stalled again, and fuel would not come out the fule tube, so something is blocking it.

>If not then perhaps the pump is shot.
Nope, new pump. Yes I have had new ones fail, but see above..

 

[mklearl]

Fuel can not come out of the fuel hose even if you drop it below the fuel tank. It is a coast Guard requirement so if your fuel line breaks you aren't continuously dumping fuel into your bilge. That is why that elbow is on the top of your tank... fuel needs to be pumped out of the tank.
How did you "check" the pump when the engine died? Did you t a pressure gauge to it to see what the pressure was?
I would still start with a filter change and run on an external tank... just my opinion.

 

[Jack2048]

>Fuel can not come out of the fuel hose even if you drop it below the fuel tank.

Sure, my boat's elbow is on top of fuel tank. At the same time the siphon action still lets the fuel drain. Have done it several times while rebuilding the engine to check for fuel flow. See below for my tales of sorrow with LP fuel pumps.

I thought about what you wrote about the fuel pump. I re-examined the situation this morning.

It is the LP fuel pump. I have had a lot of problems in this area. I replaced two sierras. After the second one, I contacted Sierra and they said there was a known problem with that particular model. They suggested I get an oem Volvo pump. When I called up Marine Parts Express, they mentioned the Sierra model before I did and said a lot of people had been complaining. So, BIG problem for them.

I have a Sierra HP pump. No problems.

The LP pump in there now is a Volvo with less than 20 hours on it. Purchased mid October last year. Worked great until I started it up.

I have another LP pump that I bought and used before I realized it was the wrong model for my engine. That has many hours, works great, but whines because it has a higher output rate than needed. Swapped it in, everything worked great. New pump fails after about three minutes. So, I know it is the pump.

Now to check the warranty.

Thanks for your help.

 

[mklearl]

>Fuel can not come out of the fuel hose even if you drop it below the fuel tank.

Sure, my boat's elbow is on top of fuel tank. At the same time the siphon action still lets the fuel drain. Have done it several times while rebuilding the engine to check for fuel flow. See below for my tales of sorrow with LP fuel pumps.

Must be a pretty long hose or the tank is above your head to get enough suction to pull fuel out without a tank.

 

[Jack2048]

Not really. Two maybe three feet long.

 

[mklearl]

I had 150 gallons of 10 year old fuel in my tank. I was doing everything I could to get a syphon going directly out of the tank... Couldn't do it. When I started thinking about it, it made sense as to why the elbow was on the top of the tank... I ended up using an electric fuel pump to drain it.
At any rate, I hope you are right about the fuel pump. Good luck!