5.7 EFI runs for 10 seconds and dies

R&D Boat Repair

Recruit
Joined
May 1, 2020
Messages
4
Even Mercury Marine has no idea! Turn the key and the boat alarms sound and fuel pump pressures up, engine starts and runs for 10 seconds, then fuel stops squirting into the throttle body and the engine dies, alarms then sound. Please help!

The following has been replaced or checked:
Oil Pressure sensor replaced.
Both wiring harnesses have been replaced.
ECM diagnosed and swapped out.
Ignition module replaced.
Both relays checked.
Ignition bypassed.
 

R&D Boat Repair

Recruit
Joined
May 1, 2020
Messages
4
The new wiring harness has a new connection to the throttle linkage that was not there before. Any chance this is related to the problem?
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
43,248
Even at 28 it should idle
If the injectors are being turned OFF by the ECM, then I would have the ECM tested

If you can keep the motor running by giving it more throttle then it might be the IAC

Don't know what new connection your discussing unless its the in-gear switch. The older motors didn't have one of those.
 
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