my renault megane{2002 1.4}has starting juddering,sounds like one of the plugs has gone its losing power too.wondered if it could be fixed changing all the plugs?
More than likely to be the coils that are breaking up, rather than the plugs - but its not a bad idea to replace them. One coil per cylinder, depending on the engine type, although some engines have one coil pack with 4 HT leads coming from it. Both prone to failure!
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