mercruiser 5.7 EFI 2001 will turn over but will not start PLEASE HELP

[Iflyskyhigh]

HI EVERYONE! My name is Tom I'm new to here and hopefully can get some help on fixing my boat... thanks in advance... so I have a 2001 Stingray 240LS 5.7 EFI. while on the water last weekend i went through some waves and as i attempted to slow down to keep the boat from bouncing so much it died on me... never started back up had to be towed back... after getting home i did some trouble shooting and still no luck... replaced the starting coil, distributor cap, fuel water separator, spark plugs(second set this year, changed the wires and plugs, oil and oil filter at the start of the season) cant seem to figure it out... just last night i have found two black wires that have came loose from somewhere deep towards the back of the engine compartment...(i'm thinking it's some sort of a ground wire.... is it possible it's the reason that the boat does not start up?) any other advice would be much appreciated

 

[alldodge]

HI EVERYONE! My name is Tom I'm new to here and hopefully can get some help on fixing my boat... thanks in advance... so I have a 2001 Stingray 240LS 5.7 EFI. while on the water last weekend i went through some waves and as i attempted to slow down to keep the boat from bouncing so much it died on me... never started back up had to be towed back... after getting home i did some trouble shooting and still no luck... replaced the starting coil, distributor cap, fuel water separator, spark plugs(second set this year, changed the wires and plugs, oil and oil filter at the start of the season) cant seem to figure it out... just last night i have found two black wires that have came loose from somewhere deep towards the back of the engine compartment...(i'm thinking it's some sort of a ground wire.... is it possible it's the reason that the boat does not start up?) any other advice would be much appreciated

:welcome: to iboats Tom

Need to know if you have a throttle body injection or MPI (engine serial numbers are best). Also need to find out if you have a fuel or spark issue. When you turn the key to ON do you hear any beeps and do you hear the fuel pump run? Pull the coil wire from the distributer and hold it close to a ground, then have the engine cranked over to see if your getting spark.

 

[thumpar]

Stop throwing parts at it and do diagnostics. Like AllDodge posted you need to figure out if you have a fuel or spark issue. Black wires would be grounds but since they build wiring harnesses for multiple different configurations they may or may not be needed. It is pretty common for some wires not to be used so I wouldn't say that is the problem for sure.

 

[Iflyskyhigh]

Hi guys and thank you for the info...
so the serial number is M003064,

I do hear the fuel pump come on and i have also tested with a noid light to see if the injectors are getting the signal and it showed as a good signal,

and i have also bought the spark test tool and checked some of the plugs i do get a spark...

it seems like the engine was running rich to me before this happened since when i changed the plugs they were black... keep in mind they were in only for about 20hr....

if you guys have any more ideas please let me know... and once again thank you in advance

 

[Iflyskyhigh]

Hi guys and thank you for the info...
so the serial number is M003064,

I do hear the fuel pump come on and i have also tested with a noid light to see if the injectors are getting the signal and it showed as a good signal,

and i have also bought the spark test tool and checked some of the plugs i do get a spark...

it seems like the engine was running rich to me before this happened since when i changed the plugs they were black... keep in mind they were in only for about 20hr....

if you guys have any more ideas please let me know... and once again thank you in advance

 

[alldodge]

Hi guys and thank you for the info...
so the serial number is M003064,

I do hear the fuel pump come on and i have also tested with a noid light to see if the injectors are getting the signal and it showed as a good signal,

and i have also bought the spark test tool and checked some of the plugs i do get a spark...

it seems like the engine was running rich to me before this happened since when i changed the plugs they were black... keep in mind they were in only for about 20hr....

if you guys have any more ideas please let me know... and once again thank you in advance

There is a Schrader valve behind the throttle body, find out if fuel is present when center of valve is pressed in (wear safety glasses). Need to find out if you have 43 psi pressure or there about after the fuel pump stops running

 

[Bondo]

Ayuh,..... Welcome Aboard Tom,..... Do ya have 12v at the coil's (+) terminal, with the key "on",..??