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454 mag mpi issues past 3/4 throtfle

Old 07-31-2020, 08:09 PM
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Default 454 mag mpi issues past 3/4 throtfle

I have a 454mag efi with procharger . This season it is missing and wont pull rpm past 4500 . I changed wires plugs distributor rotor fuel filter but still runs like **** past 3/4 throttle. Runs fine every where else.
any ideas ???
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Old 08-01-2020, 08:28 AM
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did it use to run past 4500rpm?
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Old 08-01-2020, 11:21 PM
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Originally Posted by sutphen 30 View Post
did it use to run past 4500rpm?
yes
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Old 08-02-2020, 08:00 AM
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What is fuel pressure doing when runs bad?
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Old 08-02-2020, 10:09 PM
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Originally Posted by liberator221 View Post
What is fuel pressure doing when runs bad?
It doesnt seem to drop at all
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Old 08-08-2020, 09:22 PM
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Figured it out new ac delco marine plugs gapped to 37 thous . Just happen at 4 grand i was making enough boost to blow out the spark
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Old 08-17-2020, 09:54 AM
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Originally Posted by Plus Man View Post
Figured it out new ac delco marine plugs gapped to 37 thous . Just happen at 4 grand i was making enough boost to blow out the spark
i am having the same problem. What were they gapped at before? I have a 502 with a side whipple.
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