Misfires, cutting out, failure to start

There is a single reason why this is happening to your engine, and it’s faulty fuel injectors. Initially, this problem seems harmless and not as severe, but can and will get progressively worse over time. You can easily inspect your engine for this. Just check the casing with the fuel injectors. 

If you see any leaking, you have identified the problem. Sadly, there isn’t much else you can do, but at least you know what the issue is, and you can take your boat to the mechanic knowing what the issue was.

Fuel contamination

A contemporary diesel engine is a fine-tuned machine. In order to run, it delivers pressurized diesel fuel into the engine in small quantities very frequently. That means that the fuel it uses needs to be very pure. However, in the real world, there are numerous contaminants which can cause a malfunction. Be careful when putting fuel into your tank, especially if you are pouring from a canister. Here are some common fuel contaminants and how to deal with them.

·         Air – If air enters the injector pipe, it will cause the engine to cut out. Air will depressurize the chamber, and without pressure, fuel cannot be sprayed into the cylinder and burned. There is a simple solution to this problem; bleeding the fuel system. Engine manufacturers have made this easy. There are several bleed valves in key positions. You can just open these valves and let the excess air out. Once you have done this, find the original source of the leak and repair it. It's most commonly found somewhere between the tank and the lift pump.
·         Water – If your fuel is contaminated by water, your engine may cut out as well. This can be a serious problem, but there are ways to fix it. Same as with air, you need to bleed the system of excess water. Additionally, you will need to replace the filters, since they have certainly been damaged by water.

Raw water

Older marine engines are cooled by water, rather than with specialized coolants. More often than not, these engines use seawater, since it is readily available in large quantities. However, the seawater which exits the system is typically quite hot, and hot salt water is very corrosive. This can cause some issues, such as overheating, steam rising from the engine and loss of power. There are some things you can do to prevent or reverse this problem, however. The first thing to do when you detect overheating is to check if raw water is getting into the system. Make sure that the valves are clean and opened. If that is not the issue, check the raw water pump. 

If none of these troubleshooting tips have helped you, it is likely that your problem is a bit more complicated and requires an expert’s eye to diagnose and repair. If you need Volvo Penta repair in San Diego, contact PCE. With over 40 years of experience with all things marine and diesel, this is the best place for your diesel engine repairs and maintenance.