I have a problem with my fuel supply. When I purchased the boat (Cal 3-46) the previous owner told me to watch the vacuum gauge and switch fuel tanks when the vacumm showed above 5. Indeed, if I don't do this the engine dies (usually after about 8-10 hours) and will not restart (without being bled). This is obviously not a desirable situation since it can (and has) happened at very inopportune times (recently when entering a channel with shoal areas and breakers for instance). I am assuming that a vacuum is being created in the fuel tank for some reason. I would have thought that the fuel overflow vents would allow air in to prevent this? If anyone can help explain and/or suggest a fix I would greatly appreciate it (as would my first mate who is about to abandon ship if I can't correct it!). Thanks, Gary
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What kind of engine do you have?
Vacuum gauge? I cannot recall seeing a vacuum gauge on a boat ever. If there is a vacuum gauge on the fuel tank, that is even more curious. As I understand fuel systems, the tank should be properly vented - no need for a gauge that I can think of.
Vacuum gauge? I cannot recall seeing a vacuum gauge on a boat ever. If there is a vacuum gauge on the fuel tank, that is even more curious. As I understand fuel systems, the tank should be properly vented - no need for a gauge that I can think of.
Doesn't sound like vacuum
It sounds like low fuel to me. When the fuel level gets too low, it starts to suck air in with some fuel thru the pick-up tube. It stalls because of the air. Hence, having to bleed the system after it stalls. Especially after 8-10 hours. You must have two small tanks. Also, why switch over? If the tanks can balance between one another, leave it that way and monitor your fuel consumption. Top it off when you get down a few gallons. That is, treat the combined tanks as one. Vacuum guage? Never heard of one on a diesel. Espaecially to monitor a fuel tank level.
It sounds like low fuel to me. When the fuel level gets too low, it starts to suck air in with some fuel thru the pick-up tube. It stalls because of the air. Hence, having to bleed the system after it stalls. Especially after 8-10 hours. You must have two small tanks. Also, why switch over? If the tanks can balance between one another, leave it that way and monitor your fuel consumption. Top it off when you get down a few gallons. That is, treat the combined tanks as one. Vacuum guage? Never heard of one on a diesel. Espaecially to monitor a fuel tank level.
Do your tank vents vent?
I've heard of (but not experienced myself) tank vents becoming clogged with everything from spider webs to bottom mud(when the boat was aground on its side). Are your vents actually clear to prevent the vacuum?
I've heard of (but not experienced myself) tank vents becoming clogged with everything from spider webs to bottom mud(when the boat was aground on its side). Are your vents actually clear to prevent the vacuum?
heed help??/
If you need help we can come and see how to fix the problem.We work for charter fleet and sometimes have the same problems. awayocean@yahoo.com This is my mail.We can check for free. http://www.shelterislandsailing.com/
If you need help we can come and see how to fix the problem.We work for charter fleet and sometimes have the same problems. awayocean@yahoo.com This is my mail.We can check for free. http://www.shelterislandsailing.com/
loss of fuel
I think if it were a vacuum problem you would first experence noticible loss of power. I suspect you are runing out of fuel, hense the need to prime (bleed) the system. You might want to inspect the fuel pick up tube, it may be cut too short. Assume nothing. You need to know. Al
I think if it were a vacuum problem you would first experence noticible loss of power. I suspect you are runing out of fuel, hense the need to prime (bleed) the system. You might want to inspect the fuel pick up tube, it may be cut too short. Assume nothing. You need to know. Al
Vacume gauges are very common
Vacume gauges are very common... I Installed one on my boat between the primary fuel filter and the engine. It can be the very first thing to indicate the filter clogginng, or another problem upstream of the filter... Brian
Vacume gauges are very common... I Installed one on my boat between the primary fuel filter and the engine. It can be the very first thing to indicate the filter clogginng, or another problem upstream of the filter... Brian
Vacuum in fuel tank
The fuel tank should be under no circunstances under vacuum,you must have an vent line as to compensate the fuel you are consuming with air comming in,otherwise the vacuum will rise to a point where the engine will stop.Every tank has an vent line which some times is the same as the overflow line,check and you will solve the problem
The fuel tank should be under no circunstances under vacuum,you must have an vent line as to compensate the fuel you are consuming with air comming in,otherwise the vacuum will rise to a point where the engine will stop.Every tank has an vent line which some times is the same as the overflow line,check and you will solve the problem
vacume gauges
Flybri is exactly right about the vacume gauge, it indicated the filter restriction or vacume (draw) created by the fuel pump.When the filter is cloged it will read higher. Change filters and problem resolved.I am not sure about switching to the second tank except that it might (should) have a seperate filter on it. Not sure the boat came with two fuel tanks,so maybe the previouse owner did some customizing. There should also be a filter on the engine that needs to be changed.You may also need to have the fuel "polished" and or have the tank cleaned out.Sounds like you need to have someone check out the entire fuel system and get it in shape. Not a real problem and even doable by yourself if you are mechanicaly handy. Good Luck !
Flybri is exactly right about the vacume gauge, it indicated the filter restriction or vacume (draw) created by the fuel pump.When the filter is cloged it will read higher. Change filters and problem resolved.I am not sure about switching to the second tank except that it might (should) have a seperate filter on it. Not sure the boat came with two fuel tanks,so maybe the previouse owner did some customizing. There should also be a filter on the engine that needs to be changed.You may also need to have the fuel "polished" and or have the tank cleaned out.Sounds like you need to have someone check out the entire fuel system and get it in shape. Not a real problem and even doable by yourself if you are mechanicaly handy. Good Luck !
Thank you for offering to help
Assen, thank you for your offer. Unluckily, I have now moved the boat down into the Sea of Cortez and notice you are in San Diego. I agree with most of the comments that it seems like a low fuel problem and the suggestion that the fuel pick up tube may be too short is a good idea. However, that would not account for the vacuum gauge reading higher over time, which it does (or did, for some reason it isn't working at all right now, another thing to fix). Also, it bleeds and runs fine without new filters, so it is not a clogging problem. I'm still stumped. Gary
Assen, thank you for your offer. Unluckily, I have now moved the boat down into the Sea of Cortez and notice you are in San Diego. I agree with most of the comments that it seems like a low fuel problem and the suggestion that the fuel pick up tube may be too short is a good idea. However, that would not account for the vacuum gauge reading higher over time, which it does (or did, for some reason it isn't working at all right now, another thing to fix). Also, it bleeds and runs fine without new filters, so it is not a clogging problem. I'm still stumped. Gary
Your Fuel Tank
may be full of dirt and growth. before you do expensive repairs, check the condition of the fuel and especially change the fuel filters. Also, as someone else reccommended, be sure the vent is venting, may just be a simple blocking of the vent. Good Luck!
may be full of dirt and growth. before you do expensive repairs, check the condition of the fuel and especially change the fuel filters. Also, as someone else reccommended, be sure the vent is venting, may just be a simple blocking of the vent. Good Luck!
An easy check is to
simply open your fuel fill cap and see if it works OK. If it does, then your vent line is clogged. Stu
simply open your fuel fill cap and see if it works OK. If it does, then your vent line is clogged. Stu
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