zakh - The ignition control module being the module that sits on the wheel fender and determines the spark timing using the R16 resistor value and inlet manifold vacuum? Did your car have a low idle too? I do remember trying one at a breakers a while back but it's no harm to give it another go.

yal - S and 2 are more advanced than N, as the numbers increase so too does the retardation. I do have the feeling that you're right that I'm somehow masking over the underlying problem though .