98 454 Mag Mpi mid range missfire
#31
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Joined: Jul 2015
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From: Atlantic Southeast
Do yourself a favor and replace rusted parts whether or not they're working properly. That fuel pressure regulator hat is just waiting to rust through and cause problem, most likely on the water.
#32
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From: KY
^^ Agree, would be a good idea
Also check for a blockage going back to the canister filter. If the line is blocked, pressure cannot be regulated. Need to find out why pressure exceeded limits. Was the screen clogged?
Also check for a blockage going back to the canister filter. If the line is blocked, pressure cannot be regulated. Need to find out why pressure exceeded limits. Was the screen clogged?
#33
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screen was surprisingly clean no debris in it at all, was hoping it could be something simple like that. Took the line off the fuel separator and blew air through it no blockage in there. The vacuum line to the regulator appeared to have a little sludge in it hoping I can replace the line from cooler to motor this week and test the pressure again.
#35
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yeah waiting to get back to the boat and look at the fuel rail I’m gonna post a picture of the Engine when I get back there. It’s been raining for the past 3 days here on the east coast.
#37
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#38
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From: Antioch, IL
The modifications are really unique for a naturally aspirated boat and I hope you sort out the issue. It truly sounds like the wrong tune in the computer, there are so many variables it would almost be worth talking to someone who can look at the setup on it.
Last edited by RBeyer; 05-13-2019 at 10:53 PM. Reason: typo
#39
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From: On A Dirt Floor
The return on the regulator opens at the preset psi.Sp, if it's 40psi regulator,the regulator should be partially open just after that psi.
#40
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yes, someone mentioned that and I tested the regulator is working properly.


