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Pete, Auto Service Technician
Category: Chevy
Satisfied Customers: 28280
Experience:  14 years GM dealer Technician.
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I have a 1998 Chevy pick up c25oo, 6.5 diesel engine

Customer Question

I have a 1998 Chevy pick up c25oo, 6.5 diesel engine excellerates without using gas pedal and blows black smoke when excellerating
Submitted: 1 year ago.
Category: Chevy
Expert:  Pete replied 1 year ago.

Hi my name is ***** ***** I will be happy to assist with this today.In some cases I may need more info to assist better.I apologize for any delay.

This can be an issue with one or more of the injectors dumping fuel.I have seen stuck open injectors cause this issue in some cases and this will cause the black smoke from the excess fuel as well as the engine to rev up or accelerate on its own.

If you have not had the fuel injectors tested this should be done to see if this is the cause for sure here and any injectors at fault usually require replacement for this issue.

In some cases the engine coolant temp sensor can cause a higher then normal rpm causing acceleration issues and black smoke if it is reading the engine is severely cold all of the time.

These need to be checked into further to locate if one of these is the cause and which is the cause then repaired from there.

If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service,a rating of 4 or 5 is appreciated.You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.

Thanks Pete