99 GTX RFI wont start in water

[dmarm1996GTX]

My 99 GTX RFI won't start once put into water. I can start and lower into the water and keep it running at a rough idle take it out and it runs fine until it drops under 2-3k rpm. Once below 1500 rpm it will stall and maybe get it started again. I have read many of the posts to see if I can find the issue and have learned a lot. To date here is what I have done:
New Plugs
Clean filters and fixed frozen up fuel pump
Filled injector rail with cleaner connected to pump and turned engine over to see spray patterns and all looked good.
Cleaned RAVE valves
Had dealer check codes and reset code P0335 active signal engine speed not detected. I could not find this code documented, must be new software codes and also found that this code will be active when the engine is not running. (You got to wonder about the dealer)
Checked all sensors and MPEM voltages.
Replaced Crank Sensor the old one was reading 955 ohms, new one 930 ohms (not sure this is off that much since the bosch spec is 860 +- 10%)
Verified timing at 12 degrees
Visual inspection of exhaust for leaks
Checked wear ring and changed pump oil
With the plugs out rotated drive shaft and felt no binding or grinding

Short of taking it back to the dealer for an expensive checkup I am not certain as to what to do.
Thanks for the help

 

[dmarm1996GTX]

Additional infirmation

I forgot to add that I did the basics - new battery and check the connections. I also had replaced the rectifier last year, so I did a voltage check while running in driveway and I get 14+ volts. Also the ehaust was replaced two years ago due to salt corrosion and I bought it and ran it in lake water when I had the problem with the rectifier. Have not been able to get it to idle well since.

 

[Dr Honda]

Well... you did a lot of troubleshooting. (good for you) But you didn't check one very important thing. The Compression. Low compression will show up as not starting in the water, and if you do get it started... it won't have any power at low RPM's.

Check it, and let us know what you get.


FYI... 150 is perfect, and 135 will be the bottom end of running properly. (on a SeaDoo)

 

[dmarm1996GTX]

Compression Data

Well I have been meaning to check the compression but I could not locate my tester. Finally found it in the bottom of the tool box but it is an Automotive style and to long to fit. Instead of modifying it I took an old spark plug, ground the lip holding ceramic in and knocked out the center then tapped it with a 3/8 NF24. Used the same thread on a piece of 1/4 soft copper, screwed it in with some epoxy and attached a short 4" piece of high press hose. Any way, I was getting a solid 135 psi on both cylinders. I think my setup could be showing a little low with all the adoption.

I would think next would be to try to verify the fuel pressure is at spec, but I have not found any where to get the male/female connectors to make a gage. The more I think about it, why wouldn't I just dig up a gage, a tee, 8-10" gas line and some clamps and just cut the gas line and strap it up in the hull. What do you think?

 

[dmarm1996GTX]

I have also rebuilt the starter and cleaned all the connections again. Cranked over great in the water and started the firdt try. It then stalled. I keep cranking, but it just won't start. Pull it from the water and crank it over and it will start in a bit. Looks like it might be flooding.

Any idea's? Do I need to take it in to the dealer and have the TPS zeroed?

 

[wtrgrl]

Have your grey fuel lines been replaced? What about a carb cleaning

 

[dmarm1996GTX]

Yes all the grey fuel lines have replaced. This is a RFI, so there is only one line to the fuel injector rail.

 

[radar525]

Hi, I am encountering exactly the same problem with my gtx rfi 2001. Visited authorised dealer 3 times and no effect.
Pls let me know if you know the reason already. Thx

 

[dmarm1996GTX]

Well, I finally found the problem was with the engine. Wrong oil or no/low oil caused scoring the cylinders and pistons. Had to rebuild the top end and also figured I should do the bottom end after finding water. Once cracked open found the bearings rusted.

 

[radar525]

Thanks a lot for the answer. I changed the bearings last year but I will try to investigate the cylinders/pistons now.