496 mag strange intermittent problem
#1
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Thread Starter
496 mag strange intermittent problem
please help if possible 496 mag intermittent problem, while driving the boat starbd motor starts to run crappy , black smoke, lower rpms than other motor, if i shut off motor then the battery and wait a sec it seems to reset something, then engine runs fine, seems like an overfueling problem, stuck injector? idk one thing i noticed was when this condition is happening when you turn the key on fuel pump should prime for a few seconds then shut off , while in this condition it never shuts off. any help is appreciated.
#2
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please help if possible 496 mag intermittent problem, while driving the boat starbd motor starts to run crappy , black smoke, lower rpms than other motor, if i shut off motor then the battery and wait a sec it seems to reset something, then engine runs fine, seems like an overfueling problem, stuck injector? idk one thing i noticed was when this condition is happening when you turn the key on fuel pump should prime for a few seconds then shut off , while in this condition it never shuts off. any help is appreciated.
Check fuel pressure and need to scan for codes
Also could use your motor serial number?
#3
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yes i know it doesnt shut off while running , i shouldve specified that not while engine is running but when i turn on key to prime the system before i crank motor the pump will just keep running, seems like something is just causing fuel to dump in and not combust i will try to scan for codes and i will check fuel pressure asap. serial number M 025579 496 mag. thanks for any help
#4
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I'm thinking the injector driver but need the scan to verify
#9
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so i switched computer from working good motor to running bad motor, did the same problem to the original running bad motor thus i believe ruling out a computer issue. also test pressure at rail turn key on 43 psi, then slowly drops then start motor stays steady at 36ish psi both motors do exactly the same numbers.
#10
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As far as fuel pump staying on, i would suspect relay first ? I think.