truck runs good in morning but when run for a long time truck starts missfiring and loss of power also smells rich exhuast coming out all right all ready check control mod,spark plugs,coil all working good / /? ? ? ?

 

any ideas?????????
thank you.

 

Try running an EFI (electronic fuel injection)and TBI (throttle body intake)cleaning.... also run a combustion chamber cleaner through it to clean out alot of the carbon buildup that is on the valves and pistons heads...how many miles?

 

please, post year and engine. it is hard to guess otherwise.
sounds like you have leaking injectors, assuming it's injected car, as we don't know. gas smell outta tailpipe - too much gas in, not all burnt.
or your spark ain't worth a flip. might be leaking wires. gets hotter - voltage is leaking worse because of the insulation softening.
i wouldn't be running any cleaners as of yet. find reason 1st.

 

my truck is a 93 silverado with a 350 eng. with 100000 miles with tbi.

 

It could be your tbi is messed up. the gas smell coming from your exhaust could mean your truck is running rich. its getting more gas than it can put out it will also kill your gas mileage. I have a '95 with a 350 motor in it and my throttle body is messed up Im getting about 8 mpg