Fuel Valve problem on 2003 312

Mylo

Have 2003 312  When running motors with both fuel valves open only draws fuel from starboard tank , till I shut off that valve then draws from Port tank. Anyone know what causes this and how to fix ?

Thanks

Ian

Does it run right when you do this? Thinking blockage in line from port and sucking from starboard is easier. If you shut the crossover do both run okay on their own tanks? 

Mylo

Not sure will check that tonight. Thanks.

Ian

Another thought is are you seeing this based on gauge operation? If so, are the senders good? Reason I ask is if you have a sender that is not travelling the full depth it may be suggesting that it is using more from one tank than the other. Last year I misread the depth of my tank - 20" instead of 28" - and the sender I had was 18" but I put it in anyway seeing as the old one wasn't working and it (as expected) ran down faster than the other. (I now have a 27" unit to go in)

zaverin1

I had to replace both of my senders on my Rinker.
one had a dead spot around half mark and other would
bounce around to much when underway 

Mylo

Thanks, I will check out the senders. Maybe that's it.

Black_Diamond

The cross over valve should be closed. Each engine pulling fuel from its own tank. 

Mylo

Thanks, that makes sense, do you know what is the purpose of having the cross over valve open?

Ian

I was initially told to leave open so for even draw but closed it last year. The idea of if one is low or contaminated you can share or isolate. 

Mylo

O.K. Thanks

Liberty44140

Agree on keeping the crossover closed. On both my 310 and 342 when I leave it open, the system ends up taking more fuel from one thank than the other, path of least resistance, so I always keep it closed so my burn is even. It’s there to be opened should you need it. 

Ian

Your comment on this before @Liberty44140 is what had me close mine off. Once I put in the new sender I'll have a better cross reference of both sides.