MERCRUISER 7.4 MPI NO SPARK

[brianpb321]

My 1999 7.4 mpi sputtered out doing about 3500rpm. Only 300hrs so was not worried oil looks great. However I have now replaced distributor, coil, the harness from dist to coil, MAP sensor, solenoid, TPS sensor, knock sensor, IAC sensor, new fuse box, cleaned grounds, new battery still wont start? Dead man switch good & shifter in neutral.
Actually tried 3 different ignition modules? Please dont say fuel its not fuel..fuel does not matter if no spark..but has new fuel pump, new injectors, new fuel filter despite fuel looks perfect. Its like the thing is grounding out???? Drawing lots of amps now to turn it over.

 

[Bondo]

Ayuh,..... Welcome Aboard,..... Have ya done any diagnosis, rather than just throwin' parts at it, hopin' to find the problem,..??

I'll move this to the Merc I/O forum for ya,.....

 

[Scott Danforth]

Have you followed the troubleshooting guide? Or just throwing parts?

Almost never the coil

 

[dubs283]

New distributor?

My guess is main or fuel pump relay. Possible fuel pump. You say you have no spark but have you verified this? Key on engine off does fuel pump run/prime?