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

1998 12v miss fires and w/ high egts

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Old Dec 21, 2013 | 07:01 PM
  #1  
hotlb7's Avatar
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ATTN 1998 12v miss fires and w/ high egts

So I inspected all my boost lines today no leaks @ 30psi
And My egts are crazy/scary high like 80mph @ 14000 with very odd power, that strong pull isn't there ya know? Changed the fuel and are filter few days ago Then sounds the engine its miss firing? 1200-2300rpm
Think an injector A is stuck open? Bad lift pump? Timing issue? And At a higher rpm she really misses. The engine idles @300F and she is kinda rough on idle. The high egts and the miss firing me driving me nuts! Plz help with suggestions thanks.

Quick review on mods sorry new truck will update layer
Hx35 turbo
#10 fuel plate
K&N system
Banks big head and 4 inch
5spd
3.54
 
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Old Dec 21, 2013 | 10:43 PM
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well idle should be in the 750 range
if an injector is stuck it will be smoking like hell
same goes for slipped timing
what brand gauge are you using??? a quality pyro is nice
if it is getting hot you are getting fuel so fuel filters and junk like that you can mark off.
system tested to 30psi but what are you running @ wot boost wise?
and im assuming 14000 is really 1400 as you would have a new world record on EGT temps.

the miss fire is curious. is it a stumble, is it something that is constant @ that rpm always? when does it go away? this could be a different problem (could)... a weak over flow valve can cause a stumble, a worn DV can in rare occasions cause similiar stumbles. air in the lines can cause stumbles. but im most of these cases EGT's are lower because there is less fuel to try and burn.
 
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Old Dec 22, 2013 | 07:34 AM
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94 12valve's Avatar
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check your timing sounds like it slipped
 
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Old Dec 22, 2013 | 02:24 PM
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Hopefully no burnt pistons
 
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Old Dec 22, 2013 | 11:08 PM
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might also check valve lash, one or more of the jam nuts might have come loose .... and since u recently did filters,check and make sure u didnt tear an o ring or such ...air intrusion can be quite problematic and do real strange things ... also ... gently check lines from IP TO INJ ... about 26-28lb of tq ... make sure one isnt loose
 
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Old Dec 23, 2013 | 08:47 AM
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Wot boost will it 30 quick w/ egts almost move just as quick! Timing is stock I havnt touched it
So I don't see why the timing slipped. Also check my ofv and the spring and ball are nice and tight it and the pyro I'm using is a isspro gauges. The other day it did stick to 2k rpms for a sec then never again same with the check engine light on then off
Imma gonna check again for air leaks. I'm even gonna take my intake grid off to she if she's plugged mAybe even clean the injectors, I'm not to fond of the p pump so I'll leave it as is.
Thanks for the help and tips guys
.
 
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Old Dec 23, 2013 | 02:26 PM
  #7  
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pulk the air intake off the turbo and see if the turbo spins freely and check for slop laterally and thrust in &out .... if ur turbo is locking up this will all be the type of issues
 
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Old Dec 23, 2013 | 08:30 PM
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94 12valve's Avatar
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something else easy to check is the fuel filter if you have not changed it in a while change it
 
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Old Dec 23, 2013 | 09:05 PM
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yup, when all else is with out fail ... fuel filter everytime ..
 
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