View Full Version : 1999 x-star cold start good hot start bad

06-29-2009, 11:38 PM
Boat starts great every time off the trailer but once it warms up it will crank but not start. I've worked through other posts to try and find the answer to my problems and they have helped provide guidance but I have not fixed it yet. Here is what I have done so far.

checked for fuel pressure when key is turned turned on but not cranking starter. When the problem occurs there is not fuel pressure.

the fuel pump does not run when key is turned to this position again when the problem occurs, I can hear it run when the boat is cold and the problem is not present.

tonight I pulled the connector apart at the fuel pump. The connector had three wires gray, green and black. It appears the gray is the hot wire and the others are ground. When the boat is cold and I have a test light on the gray wire it lights when the key is turned to on position, when the problem occurs the light does not come on when the key is on. I hot wired the fuel pump as the problem was happening and it still would run so that leads me to believe that the fuel pump is not the problem and that it is something in the circuit related to the gray wire. I'm going to check and work on all connections but feel it is a sensor of some sort because of the consistency of boat cold no problem boat hot won't start because of no fuel.

I know similar posts often lead to discussion of vapor lock and heat soak. This may be the case for me but I'm doubtful because the boat has done it on some very cold days in March in Missouri. Perhaps enough heat is still built up in the engine compartment but it seemed other posts talked that cases of heat soak would be in hotter regions than where I live.

Any help is appreciated.

07-06-2009, 10:56 PM

07-06-2009, 11:26 PM
You can't have vapor lock with the pump in the tank. Look near the ECM for three fuses and relays. Unfortunately, they put these under the spot where two panels of the sun pad join and water can get in. If the fuses, relays or relay sockets are corroded, clean them with Tarn-X, CLR or something like that but don't get things too wet. If your ECM has a metal cover over it, yours was probably addressed when the bulletin came out. If the fuses and relays look good (bright brass, not like an old penny), disconnect the battery cables and unplug the main harness (both plugs) from the ECM and look at the pins. If you see corrosion, make sure to dry it and blow any moisture out of the plugs. If you see this, contact MC and ask for a recommendation, especially if you see any missing pins on the ECM.

Also, go to the starter and solenoid to make sure the nuts that hold the battery cables on are clean and tight.

07-07-2009, 10:05 AM
Thanks Jim, if memory serves me right the ECM had the black metal fins but I don't remember any shield over it. I will check tonight. Thanks again.

07-07-2009, 10:21 AM
Thanks Jim, if memory serves me right the ECM had the black metal fins but I don't remember any shield over it. I will check tonight. Thanks again.

They all have black metal fins (for cooling) but if it's under the split in the cushions, it needs to be protected from water splashing/falling onto it. Contact MC to see if they have any of these if yours doesn't.