# 1990 chevy truck running rough no power



## kitti61 (Aug 23, 2010)

it is a 350 chevy silverado. Did a complete tune up, changed ox sensor, plugs, plug wires, dist. cap rotor button fuel filter and air filter. and timing.. cat gone. fresh gas. no power at any speed. hot or cold. rough idle. Truck has 45000 orig miles. Thanks for any input. Bob


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## kjms1 (Jun 4, 2010)

20 years old? .... have you owned the truck since day 1 


might want to check the exhaust system an see if it is stopped up & you might need to do a compression test


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## kitti61 (Aug 23, 2010)

I bought the truck when it was 2 years old. Compression test is a good idea. Exhaust is not clogged up. Thanks Bob


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## Gloodt (Aug 27, 2010)

The rough idle may check the egr valve see if it is clogged or not working. If that ok check for a vacuum leak.


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## kendallt (Feb 21, 2007)

Sounds like the timing chain. Chevies are good at eating them in relatively short mileage
Pull the distributor cap and plugs, rotate the crank forward by hand (socket on the balancer bolt) till the rotor moves to take up slack, then turn the crank backwards till the rotor moves again. Should be very little movement of the crank before it does. If you get say an inch or more of movement at the edge of the pulley before moving the rotor, the chain is stretched.


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