It doesn't always do this but sometimes when I start up my engine and start to accelerate it makes a hissing sound and I have no power and it starts rolling black smoke then quits and drives normal. Sometimes this occurs for just a second and once it happend for about a half mile.
Its a valve under your turbo used to help the truck reach operating temperature faster. Most guys just gut the butterfly valve inside the exhaust housing cause it really doesn't help with temps that much. Do a search, either here or on google and you will find more than you can handle about it.
Search: 7.3 powerstroke EBPV removal
05 F-250 Crew Cab Short Bed
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