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Old 08-03-2021 | 02:07 PM
  #91  
cheech
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Throttles at the helm opening up the throttle body butterflies all the way?
Do you have O2 sensors in the headers in the boat?
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Old 08-05-2021 | 08:16 AM
  #92  
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Originally Posted by zz28zz
Was alternator used when running on dyno?
If not, maybe rectifier is going bad and causing elec noise??

Are batt switches set to "1 on 1" and "2 on 2" or are they both set to "both"?? Reason I ask is I recently lost a MSD box on my port eng (#2). Tach started jumping around, then a few stumbles, then dead. While idling back in on one eng, I switched both batt switches to "both". Tach on good eng started jumping around. Set both batt switches to "1" and tach behaved the remaining 2.5 hrs idling back in.
Tes the alternator was used on the dyno. I've tried all different combinations with the battery switches and haven't seen any changes.
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Old 08-05-2021 | 08:20 AM
  #93  
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Originally Posted by cheech
Throttles at the helm opening up the throttle body butterflies all the way?
Do you have O2 sensors in the headers in the boat?
Yes we've checked and the throttles are fully open when the sticks are pushed forward.

i do have bungs installed in the headers and we have checked AF ratios - all checks out
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Old 08-05-2021 | 10:01 AM
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you have knock sensors on these motors?
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Old 08-06-2021 | 09:38 AM
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Originally Posted by sutphen 30
you have knock sensors on these motors?
Yes and I've tried disconnecting them also
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Old 08-06-2021 | 09:52 AM
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Disconnecting them doesn't always help. Typically When ECu notices knock sensor system not working correctly, it will go to preprogrammed 'safe' timing table. Read, less power. And you need power to get engine to enough rpm for the Prochargers to start doing their thing.
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Old 08-09-2021 | 05:19 PM
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Originally Posted by SB
Disconnecting them doesn't always help. Typically When ECu notices knock sensor system not working correctly, it will go to preprogrammed 'safe' timing table. Read, less power. And you need power to get engine to enough rpm for the Prochargers to start doing their thing.
We hooked up a computer to read the Map sensors - wouldn't this show up when reading here? Also would it be different on the dyno vs in the boat?
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Old 08-10-2021 | 04:17 PM
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Can you datalog the ign advance? If not, can you get a helper to check the ign timing on the fly to verify it's not retarding for some reason?
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Old 08-10-2021 | 04:39 PM
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Originally Posted by zz28zz
Can you datalog the ign advance? If not, can you get a helper to check the ign timing on the fly to verify it's not retarding for some reason?
we did datalog it at WOT and it was pulling timing out as it should have
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Old 08-13-2021 | 12:44 PM
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Do you have full (all sensors) datalog files from both the dyno and on the water to compare? If so, can you post them us to see?

Were the same grounding point/s used on the eng when on dyno vs in boat?
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