12 Valve 2nd Gen Dodge Cummins 94-98 Discussion of 12 Valve 5.9 Liter Dodge Cummins Diesels with P7100 Injection Pumps

rack plug question

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  #1  
Old 05-30-2014, 09:25 AM
cummins Pride's Avatar
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Default rack plug question

so i bought the rack plug/mac plug whatever you guy prefer calling it and i am having a guy tell me not to run it, it can cause the shaft to stick and run away. Is that true and cant i just unscrew the old plug and slap the new one. which i did and i have the injection pump off of the truck
 
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Old 05-30-2014, 04:22 PM
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As long as you're running a plate it should be fine. If you take the fuel plate out though, there could be an issue. Don't take my word for it though, wait for somebody else to chime in.
 
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Old 05-30-2014, 07:05 PM
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fact of the rack plug is that the barrels only can spin so far before they actually start de-fueling the opposite way. this is in the 19-20mm rack travel rhelm. a 2095 will allow for 21mm of travel so in some cases at WOT you can loose a little bit with a plug. as far as a runaway thats pretty crazy unless you have damaged barrels and plungers and they stick once they now rotate into an unworn area of the bores. super tight tolerences, metal to metal in the barrel and plunger assembly. so tight pressurized fuel cant pass through so if there is scoring you could stick a rack.
 
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Old 05-30-2014, 08:14 PM
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I was informed that unless you remove the fuel plate all together, the 2095 plug is not ever touched as the plate limits travel. Is that not the case?
 
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Old 05-30-2014, 08:26 PM
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That's what I was told as well.
 
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Old 05-30-2014, 08:54 PM
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if you utilize a stock profile plate i believe that is true.
 
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Old 05-30-2014, 10:25 PM
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use a #0 plate ... ditch the plug and dont worry about having an engine that Over Speeds ....

Never funny ...
 
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Old 05-31-2014, 05:43 AM
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I wonder if I'm even at risk of that, with my fuel shut off on a choke cable.

This is the part where it becomes obvious that I really don't understand how it works.
 
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Old 05-31-2014, 11:52 AM
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wow ... The 2095 plug is a great upgrade for these p pumps. If installed incorrectly yes the rack can hang and cause a runaway, this was pretty common when trying to shim the stock plug or trying to shim the 2095 plug. There is a rack guide behind the plug that is held into place with the rack plug. When shimmed it is allowed to move and could cause the rack to hang.

When installing the plug do not move the throttle with the plug out this will cause the guide to move or fall out, do not add any shims to the plug other than the one provided, and make sure the plug after tightened is tight with the housing like the old plug was. After install and everything is tight move the throttle back and forth a few times just to make sure everything is ok.

To make full use of the plug you will need the correct fuel plate and a modded afc
 
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Old 05-31-2014, 05:26 PM
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Sounds like a PITA ... un needed, get a good fuel plate....

is there really and street usage to the plug or is it something that is more for competition usage ??
 


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