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95 dodge ram, 2500, 5.9L cummins.

would not start, changed fuel filter, starts, but starts hard. takes about 10 tries.
starts on first try when warm.

i have the 1995 service manual and it says it could be air in the fuel lines because of the filter change( yes, i did fill the filter with fuel).i opened the bleed bolt, pumped the primer, saw fuel, did not hear air or see bubbles. still hard starting.

the manual says it will bleed out small amounts of air on its own, so i drove it for 20 minutes, and have let it idle for an hour, still not fixed.

the manual also shows how to bleed at the fuel injection pump and the high pressure fuel lines, is this necessary?
and how do you know if you got all the air out when bleeding at the bleed bolt? do you see bubbles in the fuel, or hear air?

i have worked on gas engines, this is my first diesel.
 

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You bleed until it is constant fuel and no bubbles. It wouldn't hurt to bleed the injector lines.
 

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Like the manual says the system is self bleeding so if after 30min of driving it still has the same symptoms, look elsewere for the problem. You could have a leaky fuel line letting air into the system, or more likely you have a fuel pressure deficit. I suspect the overlflow valve or the fuel heater is letting air into the fuel.
 

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thanks "Austin The DieselTech."

"Dual K20s",

i dont want to sound like i am arguing with you, just want to understand this.

why would a overflow valve or the fuel heater cause it to start hard, but not cause it to run poorly? i mean, air is air, why does the air disappear after the truck starts and only appear when the truck is cold?

also, i dont see a "test for air leak" or a repair procedure in the manual for the overflow valve or the fuel heater, just removal instructions.
is there a way to test these? or should i just replace them?
 

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Discussion Starter #5
did i just answer my own question?

just went out to start it, tried the primer, no resistance. pumped it 30 times, still no resistance. then it started in 3 tries instead of 10. does that mean when it shuts off the fuel drains, the air gets sucked in, and now it needs to be primed before it will start ? priming chases most of the air out?
 

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im changing mine right now, wheres the primer?!
 

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On the side of the engine below the filter. There is a black button you have to push.
 

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the big black spingy thing? if so is it supposed to be hard to push?
 

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does that mean when it shuts off the fuel drains, the air gets sucked in, and now it needs to be primed before it will start ? priming chases most of the air out?
You got it exactly.

the big black spingy thing? if so is it supposed to be hard to push?
Think the spingy thing you found is probably the shutdown solenoid boot. It should be hard to push.
The primer button is on the side of the lift pump in this link> http://dodgeram.org/tech/dsl/Facts/figures/12Ve_locations-l.gif
 

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nevermind haha finished....
thanks though =]
 

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air leak is exactly right, did you put new seals on your filter?? is your filter seated properly. if you really want to test for leaks pressureize your fuel tank to about 10psi and look and listen for fuel leaks. my heater crapped out and was the source of my hard starts ( ran great while on ) i just bypassed it by running fuel line into the lift pump for the time being. i will guarantee it is an air leak, another usual culprit is the hose connecting the heater to the lift pump.
 

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12 Valve fuel filter change

This is not what i think but what is a fact. When you change the fuel filter, it is dang near impossible to actually have enough room or enough cusswords to fill the housing with diesel fuel. so, the best thing to do is to put the filter in and before you crank it, you need to loosen the "bleed" bolt located on the top left side of the injector pump. (viewed as your hanging over the driver side fender wall) once loosened, proceed to pump the primer (bottom of engine block under fuel filter) until all or most air bubbles come out and it is squirting pure diesel. then tighten the bolt and crank the engine and stand on throttle for a few seconds. it will spit and sputter for a few until all air is out.
**yes the 12 valve is self correcting as far as air in the fuel goes because it has return lines on the injectors, but when you have a large amount of air in the line (from filter change) IT MUST BE BLED !!
 

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Not so. A 12 valve will start and run after a few cycles of crank for 30 seconds and let the starter cool for 2 minutes. When it starts it will run rough for a little bit until all the cylinders join in. That's more of usage of the starter than I normally want to do, but it WILL start eventually even with an empty fuel filter. I have done this just to see if it would work.
 
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