Under the hood

The engine itself is very strong, nothing to mention about it. You might wanna check out the distributor, you'll find a Bosch or FoMoCo/Lucas distributor. The Lucas distributor (black cap, red/brown on Bosch) tends to worn much quicker than the Bosch distributor. The distributor axle will feel loose if the bearings are worn, and that ofcourse causes ignitionproblems. Also the Lucas dist. seems to gather greasy s**t inside it causing jamming on the timing. Easy to fix, just dismantle and clean everything. Breakerless ignition can be found on some models, but I have no experience on that.

On some later models there may be the Ford VV carburettor which often causes running/idling/starting problems, specially if it has a automatic choke.

The gearbox officially needs no oil change, and that causes bearing problems. It seems that after ~200000 kilometers the differential bearings have to be replaced. It all starts with a little oil leak in the differential oil seals, ending up with non-workin speedometer and a terrible noise when driving. You can change the oil seals, but that won't help you very far. The main- and inputshaft bearings are usually okay, even if you have driven almost with no oil for a while. Fixing it requires removing and opening the gearbox.

Suspension and brakes

Like many other Fords (and many cars novadays), the front springs seem to be a slight problem. It's not rare to find them in 2-3 parts. Cheap and easy to fix.

The brakes are usually not a problem, still you have to look at two things. I have experience on 2 Mk1's with a vacuum servo (mainly on 1.1 and bigger engines), and in both of them it has been leaking. If the engine stalls when you step on the brakes at idle, it leaks very much (engine gets too much oxygene and goes off). Also increasing need of force when braking. Can't be fixed, have to be replaced.

The other problem is the handbrake. When the toothing of the automatic adjustment worns out, the handbrake just doesn't hold no matter what you do. And if you find a car where it works, don't pull the handbrake very hard, eventually it will make a big bang and the auto-adjust 'hops over' and to the garage you go. Another problem with the handbrake is the little wheel that is used to connect the right side cable, it is usually stuck, very loose or maybe even missing completely.

If the handbrake fails to operate, the problem is usually inside the brake drum. Go get new parts, that's the only way. Don't try to shorten the wires and/or making a bigger wheel etc etc to fix it, been there, done that. And it doesn't work. You might try to weld the auto-adjust to a good position, but that's not a very bright idea in the long run. Cheap parts and not a difficult task.

Chassis/rust

There are a few spots that you should check specially on a Mk1 Fiesta. The fueltank cover (underneath) is most likely in bad shape. Also the 'trunk door' is propably in need of repair, specially under the window gasket. The bottom of the trunk is usually in a bad condition. And on my current Mk1 the panhard rod mounting on the chassis is on the 'fix asap' -list, since it's a major safetyrisk.

And that's about it. The Fiesta is quite easy to repair, even the worst things (the gearbox bearings) are done in a day. No special tools needed anywhere, cheap and easy to get parts.