7.4 lost power no start

I own a 1998 Mariah 242z with the 7.4 fuel injection. I recently had an issue and asking for advice. While cursing down the lake at 3000 rpm my motor just went to 0rpm no noise or any warnings. Now I noticed as well that the warning buzzer when you first turn the key to the on position doesn't work as well. I believe theses are connected to the issues. I depressed the shredder valve to see if the fuel line had pressure and there was none. I also have a mechanical fuel pump and I assume an electrical one but I can not locate the electric pump. All advice is much appreciated pals love to get here up and going soon. Thanks so much.

Does anythinh happen when you turn the key? Does anything work?

The motor cranks but will not fire. All dash gages and trim items work. Only things I have not noticed is the warning buzzer and she just will not start.

Based on your description, I'd say the connector supplying the +12VDC to the computer came apart....should have 2 wires on either end....and I think there are some 'extra' pins......

Thanks my wife said that the boat also died randomly at the dock like twice on other boating trips just prior to this huge problem and it was at docking speed. Any advice on where the connection is pictures or a good description.

to get you a start, look up at the top of this page, where it says engine diagrams, click it and type in your SN or go thru the list....you should find two diagrams, one for the engine (ECU, fuel pump, fuses, etc) and the other for the starter & alternator.....it should have red wires on one connector and red/purple on the other...they are flat, like a 4 wire trailer connector, but with weather-tite seal...

Thanks for the help. Question should the fuel rail shredder valve have pressure on it with the motor off. If so it seems that I have lost power or the electric fuel pump is bad.

If the pump was run, there should be pressure in the rail.....some will hold overnight but most will slowly bleed down over time......

Issue resolved. My ignition module was bad and that was the cause of no fuel and it also caused the preignition buzzer to not sound.

Time to burn some gas. ��