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Old 08-19-2009 | 12:41 PM
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Is there a rev limiter on 7.4L carburated engine's 1995-1997
If there is, is it in the ignition module or the knock sensor?
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Old 08-19-2009 | 03:41 PM
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If you have the thunderbolt 4 (I think ) ignition, it is in the module. It is set at 5150.
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Old 08-20-2009 | 07:43 AM
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this sys. has 2 different module's mounted on a bracket on the dist. parts book list's one is knock sensor other is ignition module, I don't know if that is still considered the thunderbolt 4 or if it is a 5, is there a 5 or just a modified 4. have 2 7.4L carb engine's, one is a 96 and will rev over 5000, other is a 97 and will not go past 4600, at 4600 it acts like it is up against a limiter.
anyone got some more info:
Thanks Larry
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Old 08-20-2009 | 09:33 AM
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My 97's did have a rev limiter ( TBV ignition) and
it's right around 4700 rpms.

A friends 96' with TBIV ignition didn't have a rev limiter.
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Old 08-20-2009 | 01:04 PM
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Yes, that year will have a rev limiter on a 7.4. From what you describe its a TB V and the limiter is in the module.
TB IV's use a separate rev limiter and they are only on Merc Racing/Blue engines.
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Old 08-20-2009 | 01:32 PM
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On my 95 454 I had it do the same thing. The fix was to replace a bad module. The othe rmodule is solely for the knock sensor.
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Old 03-24-2010 | 11:36 AM
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Originally Posted by Smitty
On my 95 454 I had it do the same thing. The fix was to replace a bad module. The othe rmodule is solely for the knock sensor.
just swaped a 454 330 1997 for a new 502, what module should i get, dont want to hit rev at 4700, hopping to get close to 4900-5000 on WOT with out hitting it. I have the two modules with the knock sensor. Should i disable the knock sensor?
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Old 03-24-2010 | 12:22 PM
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Originally Posted by ballon78
just swaped a 454 330 1997 for a new 502, what module should i get, dont want to hit rev at 4700, hopping to get close to 4900-5000 on WOT with out hitting it. I have the two modules with the knock sensor. Should i disable the knock sensor?

item # 26 for a 454 mag will have the rev limiter
around 5100

http://www.mercruiserparts.com/Show_...CAL+COMPONENTS

Why would you want to disable the knock sensor ?
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