WATER IN THE FUEL PT3/ MECHANICAL EFFECTS
DISCLAIMER: BOAT NUT IS POSTING THIS INFORMATION AS AN ADDITION TO PART1/ PART2:
MECHANICAL FAILURES CAN OCCUR FOR MANY REASONS BESIDES CONTAMINATED FUEL....
Once you have removed the contaminated fuel: By running a motor with contaminated fuel you have created an increase in the probability of mechanical failures which will relate to the performance of your motor. The length of time you have been burning contaminated fuel will have a direct relationship on the seriousness of these mechanical failures. Some or all of these effects can show themselves immediately, progress slowly or lay seemingly dormant waiting for you to leave the vessel for an extended period of time. This downtime will likely be off season storage or simply an extended period of time were the motor is not started. Your motor may have seemed to run reasonably after the contaminated fuel has been removed however mechanical issues or failures may have already started to set in. Once you begin to run the vessel again theses failures can and usually do start to effect the motors performance. These mechanical failures can include ignition system failures, carburetor failures, fuel pump failures, injector failures, spark plug failures, sensor failures to name a few. This may help you understand how water or contaminated fuel can sneak up on you and suddenly or slowly (dictated by the amount of contamination) over a period of time create performance issues with your motor(s).
You can be out enjoying a day of cruising, all seems fine with the motor performance and suddenly it just will not start or the motor begins to loose power. If you have had or do have contaminated fuel be prepared to spend some time and money having to deal with related mechanical failures. If you have had the motor tuned up while burning contaminated fuel, which is a common error. Technicians and vessel owners quite of treat the immediate problem and miss the symptom. You may find that resetting idle and timing is necessary after you clean the contaminated fuel out of the system. The year and type of motor that your vessel has will set the base line for what systems will fail and why. A vessel which is all analog and does not have an ECM has a different less components to fail then that of a digital motor with an ECM this is due to the fact that the ECM constantly requires information from all over the motor through a series of sensors to change the parameters of the fuel air mixture and the spark to compensate for the contaminated fuel. These digital motors are either fuel injection and there is nothing harder on an injector than water contamination. So lets break down the failures you can expect on these two different types of motors.
Motors without an ECM and are carbureted:
Initial mechanical failures may include the following (all mechanical parts can fail on there own due to heat and other factors. You must keep in mind: you have either had contaminated fuel or have had a combination of these failures which will point you toward contaminated fuel tank)
1- Ignition Cap and Rotor: To burn the contaminated fuel the Ignition Coil, Distributor Cap, and Rotor will eat themselves up from attempting to create enough spark to ignite the contaminated fuel in the combustion chamber.
This mechanical failure can show up initially with a burnt coil wire, failed ignition coil or combination of both. The result of this is a no start.
2-Carburetor Failure: The carburetor has ingested so much contaminated fuel that the interior components are starting to corrode and stick.
This mechanical failure will begin with hard starting and stalling at an idle. The stalling will be a particular problem when shifting as the shift interrupter stalls the engine for a second to unload the motor from the drive or transmission.
3-Spark Plug Failure: The spark plugs have had to fire and ignite contaminated fuel.
This mechanical failure will begin with the motor missing and possible backfire when running. Bad plugs will also create a hard start or no start situation. You may also notice excessive fuel burn and will definitely see a fuel slick from the exhaust on top of the water. As the plugs fail they will no longer be able to burn all the raw fuel being sent to the cylinder.
Motors with ECM Fuel Injection and Throttle Body Injection:
1A- Fuel Pump Failure: An electronic fuel pump will suffer horribly from the water that passes through it.
This mechanical failure will begin to show itself as start issues and motor cutting out until finally the motor will not start.
2A- Ignition Cap and Rotor Failure: The cap and rotor fail for the same reasons as the above list
2 with the addition of the failure of the timing advance module
This mechanical failure will begin with the motor being hard to start, continuing toward running issues that will include power loss and bumpy idling. This is called hunting once ignition systems and motor sensors begin to fail, the computer (ECM) will try to compensate. This can lead to failure codes held in the ECM. Clearing codes will require the use of a software program to access the ECM memory. Failure codes can hinder normal operating modes, by restricting full operational parameters. Locking the motor in a safe operation mode, this restricts the motors ability to reach RPM rates over a fixed level.
3A- Spark plug failure: is the same with or without an ECM. See list
3 above.
4A- Fuel Injector Failure: Fuel injectors become damaged when water is introduced into them.
Fuel Injectors can show several signs of damage by contaminated fuel, you will notice flooding as the injector will not create a nice spray but instead turn into a small fire hose. this will flood the cylinder with fuel and create a hard start condition, fowling the plug(s)
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5A- Sensor Failure: sensors that provide the computer with the information it requires to make decisions with the way the motor starts and runs.
The main sensors that can fail from contaminated fuel are the MAP sensor or the manifold air pressure sensor, TPS throttle position sensor and the IAC. The reason that these sensors fail is that it is exposed directly to the flow of air in the intake manifold and can get contaminated with water or other contamination. Or in the case of the TPS can become damp with water around the throttle body itself. If a sensor begins to fail the motor can flood with fuel, or begin to react in strange ways eventually creating start issues. If a sensor is completely shot it can lead to a no start.
Water or contaminated fuel is not the only reason why some or all of these mechanical components fail, however if you know that your fuel has been contaminated and the motor has been run with bad fuel. Or a series of failures have happened and you have repaired Ignition parts, plugs, fuel filter and the motor ran better but has started to run rough soon after "then take a look at the fuel". When hiring a service technician for motor running issues, the technician should always ask how old the fuel in the tank is. Be honest and let the mechanic know if there is old fuel or old fuel mixed with new. This can save time and money.
This is not a how to guide but rather meant to be informative for the vessel owner who has had contaminated fuel or has had a motor that has been difficult to get running correctly and has over looked the possibility of contaminated fuel.
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