2000,Mk1 Focus, 1.4 petrol hatchback, circa 119k
Recently developed a problem which i initially thought was leakage from the badly rusted exhaust, replaced both the back and centre box but still have the same problem.
Sounds now like it could be a misfire?
On idle the engine seems fine, and the RPM needle is rock solid.
Revving in neutral also sounds fine.
But under any pressure, like accelerating, a slow, jerking acceleration is given. On cruise runs grand, but going uphill the same happens and will lose power, the needle also drops 50RPM or so before recovering.
Also fuel consumption has risen significantly.
I've dropped a bit of injector cleaner in a full tank today and ran it for 50 miles but still have the same problem.
Oil change, air and oil filters, HT lead change, plugs change all only circa 6k ago (3 months-ish). Any ideas wot could be the problem?
Plan to pop new plugs in tomorrow, but the old ones look fine. Trying to start at the cheapest option and working up!