2002 GTX DI Trouble starting when warm and in water

[DanL15]

So I just finished a top end rebuild on my 2002 gtx di. Got a chance to take it out on the water the other day and it runs great and everything seems normal. After about 30 minutes or so of riding I shut it down real quick to take a peek inside the engine compartment and everything looked good. Threw the seats back on and tried to start it back up but it just cranked and wouldn't fire up. It sounded like it was cranking fine so I do not believe it is a battery issue but I am new to sea doos and could be wrong. I tried several times over the course of about 30 minutes to get it started again but no luck while it was in the water. After getting it back on the trailer it started after just a few cranks.

When I did the rebuild I also replaced the battery with a brand new one as well as the fuel and oil filters.

Does anyone have any thoughts as to what might cause this?

Thanks in advance

 

[- BiRkS_]

Quite possible that you have a weak fuel pump or leaking injectors once they get warm, but i would expect poor performance at top end.

Maybe stuck open RAVES or too much back pressure from the water?

 

[Coastiejoe]

What is the compression now that you have run the engine?

 

[DanL15]

I will check compression when I get a chance hopefully in the next few days.

Birks - it runs very smooth but I can't seem to get it above about 47. I thought it should probably go a little faster than that but again since I am new to pwcs i'm not sure. Is this poor top end performance for a gtx di?

 

[Coastiejoe]

DI skis are NO FUN when they are not running right.

Harder to diagnose, parts cost more, and few have good knowledge to really help you.

The fuel pressure with DI skis is very important. Once we get the compression, if it is good then we will go for fuel pump pressure. You want to test it BEFORE you go for a run and when it either will not start or when it is running poorly.

Often the pump does not act up until it is hot.

But,,,, one step at a time..

 

[Seadoobuddy]

You are right about the top speed. According to seadoosource.com that ski should hit 55 MPH

 

[jammin777]

did you break it in properly? if not, could have roasted the new cylinders? also what oil are you using? just trying to cover some bases here. compression ck.

 

[Minnetonka4me]

Yup do the stuff you can do, then it needs to head to a dealer or a shop with buds or a candoo and have the system checked, and have the fuel pressure tested.

Funny thing is I had a 02 that was about 700rpm short, and would sputter on start. I had it checked and everything checked ok. I swapped that motor into a 03 XPdi and used the 03 fuel rail, pump, and electronics...and zero issues. 68mph on the dreamo-meter with a 100lb chick at the bars all day long.

 

[DanL15]

So I checked the compression and both cylinders read 60?? I borrowed the compression tester so maybe it could be bad? I tried several times and got 60 all times in both cylinders which makes me think I must be doing something strange but I am pretty sure I am testing it properly. If one was reading 130 and the other 60 I would assume it meant I did something wrong in the rebuild. Since the Ski runs very smoothly and gets to 47 I have a hard time believing it only has 60 psi in both cylinders. Also It starts right away when I first put it in the water or it is sitting on the trailer I just had trouble starting it once it had been running awhile.

Also, when i pulled the plugs I noticed both had a small amount of either fuel or water on them. Couldn't really tell and didn't seem to smell to strongly

Any thoughts? now I'm REALLY confused

 

[Mekanix]

Did you hold the throttle wide open?

 

[Sportster-2001-951C-Stock]

I kinda doubt that thing would run with only 60psi, it would turn over by the starter easy though. Check ur gauge, doesn't smell right. U could have a little water vapor in there I'd release carbon seal tension and start it on the hose.

 

[Coastiejoe]

Get another gage. We need to eliminate a base engine issue.

Let's just for the heck of it ASSUME it was reading even half correct. Meaning that you are at 120 per cylinder. Even then you are on borrowed time. Could run on a trailer but not in the water in most cases

 

[DanL15]

I had throttle wide open, both plugs out and the battery is 100% charged according the the battery tender.

I will get another gauge and check again. Since it runs great and starts right away when I first get it in the water if this is how it runs on 60 psi I will just keep it running all day haha. Again, the ONLY issue i seem to be having is starting it up when it is warm in the water. Once I drop it off the trailer at the start of the day it starts like its new. Very confusing

 

[Coastiejoe]

I'm still headed in the direction of a fuel pump.

But it needs to be tested cold and also when the issue is present.

 

[Sportster-2001-951C-Stock]

I'm also leaning towards fuel pressure as well, or perhaps a leaky injector.

Might be helpful to consider the history of the ski, if one of the cylinders was roasted or something.

Try to find an fuel pressure gauge to hang on the high pressure side of the fuel rail to measure fuel pump pressure.

I think it's worth while replacing fuel injectors during a rebuild, or finding a set of professionally refurbished injectors. A leaky injector will wash the oil film off the cylinder walls if it leaks enough, and could drip fuel into the cylinder causing a flooding condition, might be another reason for hard restarts, if not low fuel pressure.

Was it water or fuel you saw in the cylinders? Some water condensation can occur from evaporation in the exhaust system but if it was fuel you saw then it makes me think an injector could be leaking.

Another cause for low fuel pressure could be the pressure regulator valve leaking as well.