hi all, i have a 1.2 8v 2002, it was fine till i parked it, then 2 hours later - trouble starting and a misfire!
engine light on - diag machine only says "misfire detected".
checked sparkes to all cylinders
new plugs fitted
injectors working
no loss of oil or water.
i have a mechanic (that i trust lol) but he is away on hols for 2 weeks. :bang:
its just had new exhaust, 4 new tires, service, its in good con, central locking and the 5 door model.
anyone any ideas on the problem?
would asking £500 as it is be unrealistic?
thanks for any advice.

Start it up with the bonnet open (in the dark) look for blue flashes. Chances are the HT leads are fubar.

Fitting the plugs may have damaged a plug lead. Check the contacts are all good. As @Fingers99 says, see if it sparks in the dark. A hand sprayer to spray water over the plug leads can help. If the leads are ok change the coil pack. If that does nothing get the ECU tested. (lots of threads on the subject).

Dont forget that starting the engine with both plugs in a pair disconnected (1 & 4 or 2 & 3) can damage the ECU - the spark energy has nowhere to go.

thanks for the replies, the leads are all ok and we have changed the coil packs over but the fault still is no.4 pot.
would a valve or gasket failure make the engine management light come on or is that just electronic problems?

It might. Compression test, dry and wet. How did you check the HT leads?

#4 is less common for head gasket failures but any one or more can be blown. Make sure the plug lead is 100% and try different spark plugs on 1 and 4

new plugs, new leads!
if i take the rocker cover off, and turn engine over by hand.... would i see the valves working (or not)? just a thought.

You'd see the cam moving. Compression test should show any issue with a valve not closing.

Try also swapping the injectors over. Although the possibility is remote, there is a chance of a faulty new spark plug, so try that, too.

Cam cover will need a new gasket. Old ones dont like being re-used

compression tested!!!
no compression on no.3 and 4 (flywheel end)!!!

what does that mean?

Head gasket has gone or (I've yet to see one) cracked head. Not a particularly difficult DIY job, maybe cost 150 quid including new thermostat, timing belt & tensioner, water pump and head skim.

thanks, i have a mechanic mate away till next week but he does quite alot of rover head gaskets. hopefully he can sort it all out. cheers

just been told that no compression in 2 cylinders means more than head gasket, more like complete engine change! ho hummmm

and finally...........
took the head off (1.5 hours inc coffee!!!) and the bit of gasket between 3 and 4 pots has completely gone! new head gasket, exhaust and several other gaskets fitted and so far so good.
whole job inc coffee and fetching gasket 4 hours and £35.

Hopefully it will hold, but the usual reason these gaskets blow is the head has warped slightly from overheating. Skimming the surface ensures it is flat. It should also have new stretch bolts as they can break when re-used.

The skimming is usually vital. (That's why I said to do it!) :bang: I've used the head bolts twice without issue -- some sources say 3 times is OK, but, then, unless you know the history of the engine......................

sorry to jump on this thread, but having a chance to really open up my punto today, i experienced a misfire at times somewhere between 3000-4000 revs under hard acceleration. whats odd is i have reasonably new 10mm performance ht leads and new sparks and dont experience any running issues under "normal" driving, but when i went full throttle it felt like a misfire and had what seemed to be a slight burning rubber smell but i cant be sure this was from me. i know my engine mounts are shot so the misfire "feeling" could be explained from that (minus the burning rubber smell) but i was curious to if and why i had the potential misfire... seems odd as normally the engine is running smooth and without issues. any ideas?