1100 fiesta 1996 N reg My Daughter boiled the engine and blew the head gasket.
When I filled it with water and turned the engine over it shot out of the filler so I replaced the head gasket and the engine runs but there is a flash and a Bang from the injector about every two or three seconds it runs lumpy and smokes like mad out of the exhaust. The bores are ok the flashing in the injector I don't understand.

any ideas ?

scrap it and get her an ST!!

Oh dear

In an old this is just disaster. I personally don't have much clue about fixing them after problems... There will be many people who will have more of an idea though so hang tight and wait until they see the thread

Get rid mate

Did you fit the timing belt back on correctly? Not thinking about the camshaft cog but rather the accessories cog. Some older cars have the distributor rotor driven by the timing belt. Just a thought as I'm not familiar with your engine...

These are distributer less ignitions I think (coil pack)
Has it blew the inlet manifold gasket as well?
Or have you already changed that?
Blow back in the manifold is due to ignition timing or weak mixture.
Has the crank position sensor moved?
Did you set the valve timing up correctly on the camshaft? (if you had the cam out?)
Are the valve clearances correct??? A valve may be partially open.
Weak/broken valve spring??

First thing you need to do is a compression test

You'll need

New head gasket
Cylinder head checked
Timing belt kit
Upper engine gasket kit
Inlet and exhaust manifold gasket
head bolts
antifreeze

And 6-7 hours labour

Not cheap....

scrap it.

I've not got any technical knowledge here but if it needs more than a couple of hundred quid spent, you should just scrap it, or sell it as spares or repair. You could get something which runs for a couple of hundred easy enough. This sounds like it's not going to be easy or cheap!

plug leads on the right way round ? sounds like its popping back