99 Air Nautique won't crank

99 air nautique gt 40

Will not run, turns over has spark at plug wire, has fuel pressure at the injector rail. new relays on the back of the motor. I pulled a spark plug and it shows no fuel in cylinders. I do get voltage at the injector while turning over the motor.   The issue showed up early this year and while troubleshooting somehow resolved the issue for about 4 hours on the lake. The boat was at an idle and just quit and has not refired since.   I have replaced the cap, rotor and coil.    What sensors or parts could cause this issue,, TFI? MAP? Distributor?

Do you also have fuel Flow at the rail when the pumps are running?   HP pump could be giving you pressure, but low pressure pump could fail and not provide fuel to the HP pump.    Welcome to the forum... Brian's google docs spreadsheet does have a cleaning the connections at the ECM as a fix for this issue, may not be your issue, but would sure be worth a try.

Do you have a high pressure fuel gauge? Should have about 39 plus or minus 3 at the schrader valve on the manifold, the injectors will not work properly with much less. You can get a set of noid lights to test the signal going to the injectors.