1st Generation Dodge Cummins 89-93 Discussion of 12 Valve 5.9 Liter Dodge Cummins Diesels with Rotary Injection Pumps

Low Power, Fuel Mileage Drop - Help Please

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Old 10-13-2011, 07:16 PM
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Default Low Power, Fuel Mileage Drop - Help Please

I have a 92 Dodge D250 with no modifications other than an Air Dog Fuel Pump and all of a sudden I have no power and fuel mileage went from 19-20 miles to the gallon to 8 miles to the gallon.....I have to put the pedal to the floor just to get up a slight incline. Does this sound like a Turbocharger? Not sure what would effect me so dramatically like this..

If it is a Turbo and I need to change, any recommendations for replacement? Can I troubleshoot myself?
 
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Old 10-13-2011, 07:34 PM
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What's the engine doing (or not, as the case may be) when it is floored going up a slight incline? Miss, sputtering? Smoke? What color? Unusual noises or smells?

Gonna need alot more information to figure this out...
 
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Old 10-13-2011, 07:40 PM
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Originally Posted by NadirPoint
What's the engine doing (or not, as the case may be) when it is floored going up a slight incline? Miss, sputtering? Smoke? What color? Unusual noises or smells?

Gonna need alot more information to figure this out...
Clouds of black smoke.....even on a straight level road I still have some smoke with no load...
 
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Old 10-13-2011, 10:02 PM
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check your air filter
 
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Old 10-13-2011, 10:19 PM
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So it's getting plenty of fuel, but not enough air - major boost leak? Torn intercooler connector?

Don't push it too hard like that - EGT will be through the roof.
 
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Old 10-14-2011, 10:46 AM
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Sad Air Filter

Originally Posted by mnwild_05
check your air filter
Replaced Air and Fuel Filters when it started....

---AutoMerged DoublePost---

Originally Posted by NadirPoint
So it's getting plenty of fuel, but not enough air - major boost leak? Torn intercooler connector?

Don't push it too hard like that - EGT will be through the roof.
No turn connectors, don't know about a boost leak but is the turbo is no working at all that would be the same? Don't know what a "EGT" is but I was on a trip back to my home and had to drive 8 hours straight in this condition...couldn't get over 65 miles an hour on the level, about 55 mph on a grade blowing black smoke the whole time...
 

Last edited by robinlbird; 10-14-2011 at 10:46 AM. Reason: Automerged Doublepost
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Old 10-14-2011, 05:01 PM
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Originally Posted by robinlbird
...the turbo is no working at all that would be the same?
Well, yeah - if there's no boost to leak in the first place, that would give pretty much the same result.

Have you actually inspected the turbo itself yet?
 
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Old 10-14-2011, 05:07 PM
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EGT=exhaust gas temperature, I agree on a possible boost leak. Look all the rubber boots over real good and check to make sure none look as if they have moved on the piping I"ve seen the clamps fail. If there are no obvious leaks do an either check. Why do you suspect the turbo, is it making extra noise or some squealing sound which could also be a boost leak? Most turbo failures on stockish engines are oil leaks and not complete turbo failure. Rocky
 
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Old 10-14-2011, 05:58 PM
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i agree with them it has to be a boost leak the stock boots tend to dry and split
 
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Old 10-14-2011, 06:24 PM
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Default Boost

Originally Posted by regor
i agree with them it has to be a boost leak the stock boots tend to dry and split
I can't find any evidence of a boost leak....I took the hose off of the intake and revved the engine and the pressure was enough it was hard to put my hand over it.....not sure how I would actually check the boost since it is a 2" line. Not sure how I would take a pressure reading to get exact measurements.??

Checked all of the boots (at Turbo, both sides of Radiator and at the intake).

Basically my theory that the turbo might be bad seemed to be false so I have no idea what to check next.
 

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