Volvo AQ170C Fuel Delivery Problem

[paulray]

6 Cylinder with 3 Solex Carbs. The carb supplying cyl 1 and 2 is running lean. I popped off the carb top and the bowl is nearly empty, while the other 2 carbs have about 1/2 the bowl's worth of fuel. Clean idle when running, and I can get RPM up to 4000 under load but it takes a bit of time. The lean carb is the first inline on the fuel delivery line. I am told that the fuel travels through the line and fills carb 3, then 2 then 1. Can anyone confirm this? (Fluid Dynamics). I was going to test the fuel pump pressure but cannot find any specs to test against. And yes, the carbs have been rebuilt and are clean, as is the strainer on the fuel pump.
Thanks for any ideas.

 

[Don S]

Re: Volvo AQ170C Fuel Delivery Problem

Once the line is full of fuel, you have equal pressure in all directions and in all lines going to the carbs. You may have a stuck needle valve in that carb, or the float is set wrong, might want to recheck it.
The fuel pump pressure should be 3.2 PSI.
Here's a link to the OEM service manual for your engine.

http://www.4shared.com/account/file/59747156/6c065c44/AQ130_thru_170_Serv_Man.html

 

[paulray]

Re: Volvo AQ170C Fuel Delivery Problem

Thanks for the link. I was thinking that might be the problem, but not so sure now. I just got back from the boat and used a primer line for an outboard connected it to the fuel line inlet for the carbs. Got only about 3 sqeezes in before it got hard. Opened up the suspect carb and it was full. Let it sit for 10 minutes and no level change. I'm thinking the problem might be the pump. This boat was rescued from a golf course field where it sat for about 6 years. It was floated a bit last year, but getting used more this year. I'm thinking the pump finally gave up. Gonna look again tonight and try to test. Thanks again.