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T. Its an 855 big cam cummins 79 vintage serial number not…

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Its an 855 big...

Its an 855 big cam cummins 79 vintage serial number not available what should the air pressure be in the air box and fuel pressure excelerates very slowly

Mechanic's Assistant: Are you fixing this yourself? What have you tried so far?

Yes checked te turbo replaced the fuel supply line and fixed the air leak on the air box

Submitted: 10 months ago.Category: Medium and Heavy Trucks
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Answered in 2 hours by:
9/24/2017
Technician: Daniel Wilson,
 replied 10 months ago
Daniel Wilson
Category: Medium and Heavy Trucks
Satisfied Customers: 6,885
Experience: Owner at DJ Wilson
Verified

Hi my name is***** will be glad to help. You should see up to around 35PSI of turbo boost with a good working turbo and lo leaks in the boost piping and intake under a load high RPM. This is a PT fuel system which is low pressure so the injectors are what atomizes the fuel on injection and the fuel is staged in the fuel rail in the head until the injector is fired by the rocker arm. Hesitation if there is no air, restrictions, or leaks to the PT pump indicates a worn PT pump. Let me know if you need more help.

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