Rusty opined in news:3f4ee5da$0$ snipped-for-privacy@hades.is.co.za:
Hi All,
>
> I recently managed to lay my hands on an older Cortina 3.0s in mint
> condition (83000 km true on clock). Drove it from the sellers house, across
> the country down to my place, about 1600 km without any problems save a
> slight jerk at about 80 km/h in one particular place. Didn't think much of
> it then but now it has developed a serious jerk / jerks at between 80 - 90
> km/h, sometimes even cutting out. Accelerating harder seems to solve the
> prolem or dropping speed to below 80 seems to allow it to come right too. I
> thought it might be some dirt in the fuel line so I installed an in line
> fuel filter but that has not solved it.
>
> Any idea's, coil? Distributer?
>
> Any comments / ideas / help would be greatly appreciated.
>
> Tia
> Rusty
>
>
>
It have a tach? Does tach glitch when this happens? {assume M/T, remeber the engine is directly connected to wheels}
Is it rpm/load related or highway speed related?
Do a full ignition tune-up and replace the coil as well, check dist plate and shaft for looseness, play, wobble.