DT466 hard to start

shortstuff

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I have a 2003 international 4300 5-ton truck with a DT466 and when it sits over night it is very hard to start. It cranks over and does not try to fire until i put either in it. When it starts it runs real rough for about 5 min until it warms up then it runs fine!!
 

Tony

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I'd suspect one (or more) of the injectors of bleeding off over night and flooding the cylinder. You'll need to do an injector cutout test to see if one of the injectors isn't firing.

You can also use an infared thermometer on the exhaust manifold and possibly see which cylinder isn't firing, if that is the case.
 

MikeM

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Check fuel pressure. If it is low the spring is bad in the reg on the back of the head, allowing the head to empty of fuel over night. Also could be a leak on the return from back of head. There are square cut 0-rings in the fuel connections on supply side and return. They get hard and lose the seal. I would certainly start with checking the fuel pressure. Common problem, and could be costing you some power as well.
 

John Kahrs

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I agree that you have leaking injector leaking down, or bad o-ring. It runs rough because the cylinder is flooded out. If you pulled an oil sample, it may show fuel dilution in the oil. An oil sample runs $10. 00 to $25. 00.
 

noway

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Does the cutout test involve you taking out the injector and seeing if it sprays fuel?
 

Tony

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No. The cut out test is done through the computer. If you don't have a scan tool for the engine, the you'll need to check the manifold temps, have the oil tested for fuel or find some who can do an injector cut out test on the injectors.
 
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