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2001 GTX RFI running on one cylinder in water

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jbringley

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Recently rebuilt engine revs fine on trailer but drops to running on one cylinder when it hits the water. Looks like it has spark at idle. Compression is good. Is there a way to check to see if the injectors are delivering fuel when it is under load? Any advice would be apreciated.
 
You might want to cut the spark plug wire end at the spark plug cap and re-install the spark plug cap to help improve the spark...Check the grounds too from the battery.It sounds like more like electrical than fuel...

Karl
 
does the boat run proper?
i think, i might be wrong, but the rfi engine does cut spark and fuel at idle to one cylinder at idle
i will check this and let you know
mud
 
If an injector is working properly it will pull the pintol needle from its seat and allow pressureized gas thru. 1. check the signal. 2. check the fuel pressure. 3 check the
Ohms resistance of the injector, as it operates like a magnetic solenoid opening several times per second. You should look in your manual for the oem spec, to determine if good or bad. When wont run in water #2 is a common fault. 59 lbs.
 
Thanks guys. I'll try a few of those things today.

I have heard that these run on one cylinder at idle but I do not think that is the case for the 2001 model... maybe older or newer ones.
 
Sea-Doo RFI Troubleshooting

--------------------------------------------------------------------------------

Understanding The Sea-Doo RFI

All RFI motors idle on 1 cyl, (The front) For 05, this motor runs off a different ecm that allows the motor to either run on the mag or the pto cylinder , it will randomly chose a cylinder and idle on that one.
RFI computers have a function that will sense the battery voltage. If battery voltage drops below 8.9 volts for 30 seconds the motor will rev-limit to 4480 rpms, If voltage drops below 7 volts it will shut down the engine completely.

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.


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