Volvo 3.0 l max RPM 3,000 under load

[Cruzan at last]

I have a 1996 Regal with twin 3.0l Volvo motors. At the end of the season I took it out and I could only get a maximum of 3,000 RPM out of the port motor. It ran like that for about 10 minutes and then just cut down to about 1,500 RPM on it's own. At this point I headed for the marina. When I lifted the engine compartment door there was a lot of water on the underside of it. After replacing the water hose that was punctured from a hose clamp end I thought my problems would be solved once the water dried up. I took it out for a test run just before I took it out of the water for the season and my problem had not changed at all. The engine started easy and ran great at low idle. Once I hit the open water it would only go to 3,000 RPM still. So I took both engines out of gear and hopped inside the engine compartment to look. Without the engine in gear I could easily get 4,000 RPM out of the motor by revving it at the carburetor and also at the shifter. The engine seems limited to 3,000 RPM when the engine is under load. It also seems that once it warms up it won't even run at idle speed, it just stalls. Any ideas on what the problem might be?? Thanks in advance!

 

[Bondo]

Any ideas on what the problem might be??

Ayuh,.... Welcome Aboard,..... Sounds like it's runnin' outa gas,... Check the fuel filter for water, 'n crud,....

 

[Scott Danforth]

in neutral the motor only needs drops of fuel to rev (no load). Under load it needs buckets of fuel to rev. you have a fuel issue. check the stuff that Bondo indicated. also, check the stickies at the top of the forum for low WOT. there are about a dozen things to check.

 

[Cruzan at last]

Thanks for the quick replies! FYI, I have changed the fuel filter every season and I don't put many hours on the motors. I have a single fuel filter that feeds out to both motors and no secondary filters. The starboard motor runs fine under load. Although the port motor will only run up to 3,000 RPM when I start out, once it's warmed up or hot, would low fuel explain why it stalls? I was thinking perhaps and ignition coil or electrical problem? I'll check the stickies. Thanks again

 

[Cruzan at last]

If I am getting water and crud in the filter from the tank, how do I clean the tank?? All I have is a 2" or so hole from the sending unit that I can use to get in and clean. I have had the boat for 5 years and I have never cleaned the tank and before that I have no idea, the tank may never have been cleaned in 20 years! Any tips on how to clean the tank would be appreciated

 

[Bondo]

I have a single fuel filter that feeds out to both motors and no secondary filters.

Ayuh,.... There should be a filter, Inside the fuel pump, 'n possibly another at the carb's inlet,....

Pull the primary filter, 'n examine it's Contents,....
If the tank has crud in it, change the fuel filter more often,...

There shouldn't be enough junk in the tank to warrant pullin', 'n cleanin' it,...

 

[Cruzan at last]

I only have one consider filter before the fuel pumps. It filters down to 10 microns. I hope to get a look at it this weekend. Thank you for your help!

 

[Cruzan at last]

Sorry, I only have one "canister filter" before the fuel pumps. Is it a common practice to clean out the fuel tank every once and a while?

 

[Bondo]

Is it a common practice to clean out the fuel tank every once and a while?

Nope,.... If there's only been clean fresh gasoline in it, there's no reason to clean it out,.....

Have ya pulled the canister filter, drained it, 'n inspected the contents of it,..??
What'd ya find,..??

Did You remove the filter from the fuel pump,..??
Why,..??

 

[Cruzan at last]

So I removed the canister filter and inspected the contents and there was some flakes in it but nothing too large and certainly not that much. There is an attached picture of the paper towel that used to strain it. I put the contents into a jar and there doesn't appear to be any water in it. Next I went and removed the fuel pump filters which I didn't even know existed until Bondo told me about it, thank you Bondo!! They appeared to be very clean, again there was a little bit of debris but nothing that would clog it enough to slow down fuel flow. I then went to check out the carburetor inlet filters that Bondo mentioned, thanks again because I didn't know it existed. In my Holley 2 barrel carb though there wasn't an inlet filter. Someone had either removed it or it was never there. There is certainly room for one in there though. I changed the canister filter and am going to order the fuel pump filters and carburetor filters. I'm just not convinced that this is going to solve my low WOT problem.

 

[Bondo]

Ayuh,... That don't look bad, I was expectin' atleast some water,....

Could be the fuel pump or carb,....

Fuel pump should push 4 to 6 psi,...