Engine miss on acceleration

[C.K. Piquup]

What would be some possible causes for engine missing when under load(accelerating)?I`m thinking a problem in valvetrain:bad lifter/burnt valve.Still has good power and miss is slight.The Suburban sat a while,I had to move it and I let it run a while(1/2hr or so).It was idling fine.I revved it and alot of smoke came from the left bank,a mixure of black and white,maybe even some blueish.I revved it(short revs)a good bit,kept smoking,by now lt.grey.I`ve been driving it some and see no smoke when revved.It`s not using coolant.Valve seals?Time for valve job before bigger trouble?128,000mi.

[jcomp]

I think I would start with replacing the fuel filter and inspecting the rest of the fuel system.

[TimK]

CK,

I would definitely replace the fuel filters as the first course of action. You said the truck has been sitting awhile. This could allow fungi to start growing in the fuel. A truck that sits without being run can also start rusting, internally. Depending on where you live and the humidity level, this moisture can start to attack internal engine components once all the oil has drained off the parts or evaporated. Humidity also becomes condensation in the crank case. I would recommend doing the less expensive items first such as filters and oil. Run the engine for awhile (such as a tank or two of fuel) and if the problem persists, then start considering the more expensive items. Such as injectors, valves or whatever. There is nothing like a batch of fresh motor oil to help loosen stick valves.

Good Luck.

TimK

[C.K. Piquup]

Thanks for the suggestions.I will service the fuel filters.When I said it sat a while,it was about a month,not that long.The smoke I saw was only from one bank.It seems something is leaking-down to piston(s).I`ll keep an eye on it.