Need help truck runs ruff need help

Sounds like you need new spark plugs and wires also a throttle body cleaning.

The naturally balanced configuration virtually eliminates shake and idle roll. The standard Vortec 4200 engine delivers the most horsepower in its segment - 275 hp with 275 lb.-ft. of torque for strong trailer towing capacity.---------------------------------------------------------------------------------------------
Audi-VW Airbag Reseter

could be a stuck egr valve

The ruff noise you have on the timing belt shows the belt quality,which is better to change the belt with a recommended by the manufacturer,for better results and more protection and safety.

Could be a problem with ECT (Engine Coolant Temperature) sensor or fuel injection system. Will need to test and check in order to discard.

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use carb cleaner spray on the inside of the throttle body.

use super unlead only to prevent buidup.

cold engine only.

hope this helps
thank you
jm

ruff idle may b idle controll senc. ----tapping may be plugs-- wires, and or gas try 91 oct gas next 3 tanks and see thats the cheeepset place to start

some of the parts and what not (ecu ect) my not work on the 92 engine. Check With dealer or on line to see what years are acctually interchangeable. It could be somthing simple like needing to upgrde a sensor or reprograming the computer. Hope this helps

dont go changing bits ,then find it still doesnt work ??chances are they are right but take it to garage as an incorrect diagnosis will cost you money in the long run

Hi you should change the coolant temp sensor this is a white sensor on top of the intake and is part ot the computer system.