1.8 16v cab playing up

[tsotd]

my mother in laws 1999 1.8 16v cab is playing up.

you can be driving down the road all fine then the next thing without warning she will start firing on 3, when it first did it she was plodding down the motorway at 60ish then it just started, she said that she pulled over to the hard sholder and turned the engine off, waited afew mins then started it up without any problems.

ive taken the car out and it done the same thing to me at a set of traffic lights, just starts firing on 3 then turn the engine off, after afew seconds a turn the car over and it run fine again.

ive plugged the car into a diagnostics machine which reads the fault as the coil packs, ive changed the coils, plugs, fuel filter, fuel rail and its still playing up as and when it feels like it. it can go afew days without any problems then it will start up again.

ive checked the compression and she reads 13 across all 4 so theres nothing wrong there.

again everytime ive plugged it into a diagnostics it reads a coil pack fault, im now on my 3rd set of coils but without any change.

any ideas?

also ive read on here that the 1.8 16v is a poo engine, loads of coil/ecu problems. why is that? poor building/planning on peugeots part?

thanks