Have you checked your ignition distributor? Those are known to cause idle issues, and much cheaper to replace than a fuel distributor. If it has not been replaced do it, see if that helps, if not it should be replaced anyway. Also the plugs and wires. I had a rough idle on a 103, it was plugs, wires, and distributor, car only had 42k on it, but now it runs wonderfully.
Brian

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Brian W. Heitman

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