2001 172 - engine missing, engine warning light on, running on three cylinders

[Nicolasticity]

Mk2 Clio 172, started missing at low speeds few weeks back. Cleaned coil and leads (did not remove intake) and OK for a morning. Sometimes gets very bad and have to change down and get the revs up or it looks like it will shake itself apart! Strangely it can be OK first thing at low temps 2 degrees say and with fuel system electronic choke working.

Indicates to me that the plugs are shot but are there more obvious faults like;

Ignition leads resistance increases at 95K miles
Coils give up at high mileage
ECO to coil wires build up resistance through corrosion.

any help as always much appreciated

 

[domjolly]

Could be a fubar Injector.


plug it in to a diagnostic machine see what it says

 

[Nicolasticity]

thanks - dont have a diagnostic machine and the symptons just feel like ignition however;

Removed intake and ignition leads, No1 spark plug end was wet and had a jelly like substance that you get on marine outboards used in the sea on lead and in the hole. Plug hole was wet and 1/4 inch of water at the bottom and corrosion on the plug. No 2 was wet, no water, No 3 had dry corrosion, No 4 less so.

Spark plus leads had signs of tracking and were stuck together.

Coil pack connections had signs of corrosion as did lead to ECU.

Got the dremel and wire brushes out to clean plug holes. Fitted new plugs, scotchbrite on the ignition leads. Thorough wash down to remove road salt.

Car starts and in two 4 mile journeys didnt miss a beat - will take for longer run in next couple of days.