Volvo aq131a won't get out of its own way

[cincy_cosmo]

Hi,

I own a 1984 Imperial 19' bowrider with a Volvo Penta AQ131a engine. I had it out last night and had one of those 'Grizwald' moments: Family all sitting, just cleared the no-wake markers and I yell HERE WE GO and then the engine died as I advanced the throttle. The boat has a history behind it (ran last summer, then suddenly ceased to start) and has recently had the carb rebuilt at a boat repair place. They said it has a 'slight hesitation' that they could not resolve and returned it to me for free. What it really has is the inability to rev (in the water) past 2200 rpm. We spent the evening putting around the lake in displacement mode.

After reading some threads here on iBoats, I tend the think the engine has a timing problem, maybe a fuel pump problem or ?? The issue is I do not have alot of automotive testing equipment (timing lights preassure pumps etc). Obviously it is useless taking it back to the same repair place. My choices are repair it myself, find another repair place on the Cincinnati area, or dump it on Craigslist as a 'unique fixer upper opportunity' to someone who does have a more equipped garage.

Ideas and opinions are totally appreciated.

 

[MikDee]

Re: Volvo aq131a won't get out of its own way

I would suspect a fuel delivery issue. Boats usually have a spin on canister fuel filter/water seperator by the fuel pump that need to be changed each season, check that first. Then the fuel line ahead of that at the fuel tank has a tiny (replacable) spring loaded antisiphon valve (for safety fuel shutoff, in an accident), along with another smaller filter, that sometimes get gummed up, blocking fuel flow some, or completely.

 

[cincy_cosmo]

Re: Volvo aq131a won't get out of its own way

I checked the fuel filter and tested the pump fairly recently, but I suppose it would be good to recheck it. It will be a day or so before I can get to that.
In the meantime, thinking ahead, if the filter IS clogged, I would suspect I have dirty or corrupt gas. Figuring out how to drain the gas is easy, but, what would you do with dirty gas?

 

[MikDee]

Re: Volvo aq131a won't get out of its own way

Just a heads up here, Did you check the fuel line at the tank? Often the (mandatory!) antisiphon valve, or in tank filter gets clogged up on old boats.

 

[Bondo]

Re: Volvo aq131a won't get out of its own way

what would you do with dirty gas?

Ayuh,..... Put an Ad on craigslist,..... It wouldn't last a Day......

 

[cincy_cosmo]

Re: Volvo aq131a won't get out of its own way

Just a note that after the weekend I found that the previous owner of the boat had added a deep discharge battery and mounted it in a cubby-hole near the fuel lines. I removed it Saturday to look around and viola! the problem dissappeared. I believe it may have been pressing against a fuel tube and crimping it some.

I have not gotten a chance to get the boat in the water yet for full testing...hopefully tonight.

 

[JAL51974]

Re: Volvo aq131a won't get out of its own way

Its surprising that the mechanic didn't spot that pressing against the fuel hose? Was that battery in a separate compartment that the fuel line ran through?

Joe

 

[cincy_cosmo]

Re: Volvo aq131a won't get out of its own way

Since the deep discharge battery was an owner add-on, it was forced back in the compartment where the fuel hoses ran. The previous owner hooked up a trolling motor and the depth finder to that battery.

I'm not TOTALLY convinced this is the problem. But like I said in the original post, the mechanic reported a 'slight hesitation'...not an out and out dies on the spot. The battery had been removed when he had it and I put it back in (ahhhhhh...the thing that changed!). I should have it out tonight, if storms don't move into the area first.

 

[JAL51974]

Re: Volvo aq131a won't get out of its own way

Testing it out tonite will tell you if you found the problem!

I would check all those filters, antisiphon valves, etc mentioned previously though if it keeps happening. Who knows you may have discovered the problem already though.

Joe

 

[cincy_cosmo]

Re: Volvo aq131a won't get out of its own way

I never did offer the end resolution to my problem...

After several trial and error test runs that were unsucessful, I gave up and took it to a professional...this time I drug the boat across the great state of Ohio to get a more experienced repair shop on Lake Erie to look at it instead of the Ohio River dealers down here in Cincinnati who only want to service what they sell...recently at that.

I took it to Mike's Dockside Service in Marblehead. In three days they replaced the fuel pump, re-timed the engine and cleaned out the carb. The primary circuit was clogged. They charged a fair amount, but as usual, you get what you pay for: the boat runs better than ever now...so much so I'm considering re-propping it with a higher pitch prop as the engine can handle it now.

Ultimately, it is impractical to travel the length of Ohio for service, so I guess I will end up buying the timing lights etc to work on this myself from now on.

 

[jerryjerry05]

Re: Volvo aq131a won't get out of its own way

Be careful when re-propping.You didn't say what you were running and the RPM at WOT.Jerry

 

[JAL51974]

Re: Volvo aq131a won't get out of its own way

Glad you found a resolution!

I have the same problem here in Steubenville...no mechanics will touch this old VP engine and drive. I learned a lot myself to do most repairs. Still need to take it occasionally to a repair shop 2.5 hrs. away near Lake Erie for the big jobs! Try to do most of it by asking for help here, these are great people and very knowledgable too.

safe boating in Cinci!

Joe