Hi all, I am a newbie to this forum.
I have a GTX 2001, fuel injected, oil injected ski. It normally runs great, pulls 2 single skiers.
It did not have full power so I thought it needed a service, new plugs etc.
After the service it was worse, even cutting out at full throttle, so I took it back and was told water was in the fuel system. It cost a small fortune to have this removed and now it is worse again!
It will start immediately, but when I give in throttle, it sometimes revs, sometimes stalls. If it runs it misses badly. It got full revs and then slowly died.
I cannot tell if is a fuel problem, air problem or electrical problem. Where is the fuel and air filter on these things?
I use the same fuel in the car and have no problems so I do not believe the mechanic when he told me there must have been water in the fuel from the servo.
Could the motor be ready to die? The compression test was OK.
Any help or previous experience on this problem would be greatly appreciated. I cannot afford to keep taking it back to the mech.
Thanks
Brian
To me, you have described a fuel pump going bad on your 2001 GTX-RFI.
Useing VCK and buds EMS is great for electrical, but not pump failure.RFI motors have 5 sensors that provide information to the fuel injection system. 1) throttle position sensor. 2) water temp. 3) air temp. 4) air pressure. 5) crankshaft position sensor. If one of these sensors malfunctions the watercraft will be put into limp mode and will be rev-limited to get the operator back to land.
RFI fuel systems. The fuel system consists of .1) the fuel pump. 2) the fuel pressure regulator. 3) the fuel filter. 4) the fuel level sensor. 5) the fuel injector. Every thing listed here except the fuel injector is located in the fuel pump assembly which is located in the fuel tank. Fuel pressure should be tested while the watercraft is under a load, due to the fact that the fuel pressure can change drastically from just checking it at idle. The correct fuel pressure should be 56-60 psi.
With the information listed above there are many variables to consider when installing a new engine and finding out that it is not running like a new engine. In most cases a newly installed engine that runs poorlyor does not run at all may be the result of a sensor malfunction, poor fuel pressure, clogged fuel filter, bad throttle position sensor or a throttle position sensor that is not adjusted properly, Incorrect spark plus and last but not least a BATTERY That does not have proper voltage while cranking over the motor.
Most of these sensors can be checked by ohms testing and the use of the factory repair manual which is highly recommended when performing an engine swap. Any authorized dealer of the brand watercraft has the ability to do complete diagnostics to find electrical and fuel related issues that might be occurring that the customer can not solve them selves.
The fuel pump setup for RFI (RotaxFuelInjection) is GM based. That is partially true, but not entirely. The pump itself is a Bosch pump that crosses to a BMW Z3, but it very similar to the pump used for a 95 Chevy Beretta. It is also the same pump used in a 97-04 Jeep Grand Cherokee. The Part number you want for the fuel pump is 69223. The fuel socks are as follows: the internal sock (inside the canister) is also for a Jeep Grand Cherokee, 97-04, Airtex part number FS220. The external sock (at the bottom of the fuel module) is for a Saturn 1.9L, Airtex #FS242. The fuel pressure regulator is for a Chrysler, returnless style fuel system. I am trying to cross the exact application, but I am betting one for a Jeep is right, but it is also very similar to the ones used in all 2g Dodge Neons (2000-2005) and PT Cruisers (all models). All of those models run at a spec'd 58psi.
One of Mine started losing prime because the rubber gasket that holds the bottom of the pump was rotted. I undo all the nuts and remove the pump as a unit from the tank, then dissasemble. I determined A mixture of one part Toluol (tolulene) to four parts gas is ideal for rejuvinating the pump. I put a short line onto the out nipple of the pump and put the pump in a bowl (1/3 full) and apply 12v and lightly tap on it, then after it begins running, if pukes the orange crap out and then runs better. After a few minutes I had a great working pump! I used a rag on a stiff wire to clean the tank. I used the mixture to clean the pump fuel sock and the filter. I found alot of debris in the fuel rail when I used the mixture. WARNING: Toluol has a very low flash point (very combustible). You will need to get in there and see.
A fuel injector is nothing more than a high-speed valve for gasoline. An engine computer or controller is used to control the fuel injector. Contrary to popular belief, this is NOT done by sending power to the injector. Fuel injectors are normally fed power whenever the ignition key is on. The computer controls the negative, or ground side, of the circuit. When the computer provides the injector with a ground, the circuit is completed and current is allowed to flow through the injector. This energizes an electromagnetic coil inside the injector, which pulls a sealing mechanism (pintle, ball, or disc) away from its seat. This makes it possible for fuel to flow through the injector and into the engine. When the computer removes the electrical ground to the injector, the electromagnetic coil becomes demagnetized and a spring forces the pintle, ball, or disc shut to cut off fuel flow. Even at an engine speed of just 1000 RPM, this is done hundreds of times per minute.
An injector in an engine turns on and off very quickly to control the amount of fuel delivered. The amount of time an injector is turned on and delivering fuel is known as the duty cycle. This is measured as a percent, so 50% duty cycle indicates that the injector is held open and held closed for an equal amount of time. When the engine needs more fuel, the time that the injector stays on (its duty cycle) increases so that more fuel can flow into the engine. If an injector stays on all the time, it is said to be static (wide open, or 100% duty cycle). INJECTORS SHOULD NOT GO STATIC IN A RUNNING ENGINE! If an injector is static in a running engine (open 100% of the time), that injector is no longer able to control fuel delivery. It is just “along for the ride”. This could be an indication that the injector is too small for the needs of the engine. Injector duty cycle should usually not exceed 80% in a running engine at any time.
The injector on the furthest end of the fuel rail in your returnless fuel injection system may be more prone to dirt contamination and clogging than injector further upstream. Because there is no circulation of fuel back to the tank, the end of the fuel rail probably has become a sewer pipe has collected debris that got past the filter.
Cleaning the injectors on the engine may not help because the debris may remain trapped in the end of the fuel rail. It may be necessary to remove the injector(s) and fuel rail for cleaning, or to replace the rail if the debris cannot be flushed out as I previously stated. Hope this Helps, Bill
