4.3 won’t start

[CurrentObsession]

2001 Stingray MS200 with 4.3 Merc antifreeze cooling.

Had to be towed in last night as the engine wouldn’t start. Had the fuel pump replaced last year. Only 2 hours on it since. The solenoids both click when turning the key half way however the fuel pump doesn’t make any noise. I checked all 3 tiny fuses next to the solenoids and they all are good.

What should I do next?

 

[Scott Danforth]

use a test light or DVM to check voltages
hot wire the fuel pump to see if that still runs

 

[CurrentObsession]

use a test light or DVM to check voltages
hot wire the fuel pump to see if that still runs

Check voltages where?
Getting to the fuel pump requires taking off the manifold.

 

[Scott Danforth]

you need to check voltages at the fuese, the FPR, as well as the pump

 

[CurrentObsession]

Update:

Mechanic installed another new fuel pump after seeing that the leads to the pump were showing 12.5 volts for a few seconds when the ignition key was turned half way but the pump was not making noise. After new pump was installed he tried to start it and it was dead. He swapped out the ECM from a different boat and it ran so he figured something wrong with ECM. I sent ECM to OBD Diagnostics in CA and they tested it and said they can find nothing wrong with it. Mechanic is now thinking new wiring harness.

Any input is appreciated.

 

[alldodge]

Mechanic installed another new fuel pump after seeing that the leads to the pump were showing 12.5 volts for a few seconds when the ignition key was turned half way but the pump was not making noise. After new pump was installed he tried to start it and it was dead.

Check the ground connection on the pump
One side comes from the FP relay which has 12V, the other goes to ground

Pic is V8 but same as yours

 

[Bondo]

Update: Mechanic installed another new fuel pump after seeing that the leads to the pump were showing 12.5 volts for a few seconds when the ignition key was turned half way but the pump was not making noise. After new pump was installed he tried to start it and it was dead. He swapped out the ECM from a different boat and it ran so he figured something wrong with ECM. I sent ECM to OBD Diagnostics in CA and they tested it and said they can find nothing wrong with it. Mechanic is now thinking new wiring harness.
Any input is appreciated.

Ayuh,....... You need to find a mechanic that can do diagnostics, rather than a certified parts changer,......

 

[Lou C]

Was the battery wiring checked, positive to starter solenoid positive, ground to engine stud near bellhousing? Was the fuel pump getting a good ground?
When I look at these schematics I am grateful to have a simple points ignition, mechanical fuel pump and 4bbl carb. But always check and verify the basics first.