6.7 cranks but no start - Dodge Cummins Diesel Forum
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post #1 of 7 (permalink) Old 03-31-2016, 11:06 AM Thread Starter
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6.7 cranks but no start

Customer brought me a truck, said he drove it all day parked it that night next morning wouldn't start. When it cranks it sounds like a truck with air in it. It hits a little but but just won't start. Bled the system , checked for codes there are none, and rail pressure is 5-6k when cranking. I was thinking cam/crank sensor but with no codes didn't want to just throw parts at it.

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post #2 of 7 (permalink) Old 03-31-2016, 11:43 AM
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You may have fuel at the rail, but are your injectors firing? Could be Fuel Rail Pressure Sensor is not reading pressure and is not sending message for injectors to fire. You might try clamping down on the Fuel pressure Relief line and see if it will start.
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post #3 of 7 (permalink) Old 03-31-2016, 12:13 PM Thread Starter
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But if the rail sensor wasn't reading I wouldn't be able to read the rail pressure right?
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post #4 of 7 (permalink) Old 04-01-2016, 10:54 AM
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I agree with what you are stating however, fuel is in the rail, but if the Pressure Sensor cannot communicate with the the Injectors for some reason, they will not fire. Therefore fuel will merely pass through the rail and back out the relief valve. There have been instances of individuals clamping down on the Fuel Pressure Relief Line and get it to start. Simply a process of elimination method without spending money. Based on you establishing you indeed have fuel pressure at the rail (5-6k) during cranking, indicates a possible electric issue. You said it, "hits a little", as if it is firing at the injector/cylinder but not all of them? "When it cranks it sounds like a truck with air in it"? Are you saying the engine spins freely as though it has no compression? I'm just trying to clarify some of your statements to help diagnose your problem.
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post #5 of 7 (permalink) Old 04-01-2016, 11:25 AM Thread Starter
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Thanks for the Input and help. The engine r hits like it wants to start but will not do so. It does not spin freely
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post #6 of 7 (permalink) Old 11-17-2016, 10:05 PM
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Quote:
Originally Posted by BHFR-CUMMINS View Post
Thanks for the Input and help. The engine r hits like it wants to start but will not do so. It does not spin freely
did you find out what was wrong?
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post #7 of 7 (permalink) Old 10-21-2019, 10:57 PM
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I’m running into this same issue. Did you ever find an outcome? Bad ECM?
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