95 cavailer runs rough at idle?

Answer 1

Don't they all. Invest in a Haynes or Clymer manual for the car. The most common causes of rough running are having an aftermarket out of spec air cleaner and/or exhaust and lack of regular servicing. After that, check the engine and manifold (if fitted) earth straps for cleanliness and security. Check for air leaks/cracks around the inlet manifold and carburettor. Wear in the carb can result in an over-rich mixture at idle. The float chamber level may also be too high. Check the exhaust manifold for leaks and cracks. In the distributor, check rotor arm shaft for sideways play and replace the distributor as necessary. While you're in there, check the auto advance bob-weights and springs for equal fly-out. (you should be able to rotate the rotor arm a short way in one direction (opposite to normal rotation) and it should return on release. Check the rotor arm and dizzy cap for signs of tracking and electrode wear. Mark up the plug leads so you know where they came from, then drag out the plugs and check they are dry and have equal colouring of deposit; should be a light straw colour. Clean them and re-gap the electrode to the vehicle manufacturers recommended width. Take off the rocker cover and re-gap the tappets. If they are too loose the valves don't open properly. Too tight and the valves never close. While you're in there check the condition of the valve stem seals, oil can leak past them and be drawn into the cylinders causing lumpy idle and exhaust smoke on acceleration. As a last resort a simple compression test will tell if the valves are leaking. If the compressions are very different the head might have to come off; but before that there are several additives that you can try to clean out the coke from the top of the engine.