Hi all, i need your help .My 87 starion idles perfectly some times (hot and cold) then it becomes very lumpy and will sometimes cut out, its done this since i fitted the motor 9 months ago .ive checked all vac pipes and turbo pipes for leaks with no luck . i also have no o2 sensor ive been told it should have one but i cant see where it would plug in ,dont know if that would cause the idel problem tho .any idea ? lee

Certain years didn't have O2 sensors. It should plug into the exhaust pipe after the manifold.
If your's hasn't got one, don't worry about it. Try unplugging the AFM (the 3 or 2 pin connector coming from the air filter) and see how it runs. Most Starions do not require an AFM to run, and some years run better without it.

They sure are strange cars, and to be honest I'd change the fuelling and ECU if you can't suss it out.