Ford Sierra 1.8 CVH (ESC Hybrid) misfire under high load, low revs.

Could be an earth fault. The symptoms below sound very similar to those I had on a Cavalier with a corroded engine earth strap, which got gradually worse before eventually dying (on a cold wet day of course).

Sounds like the problem 2.0 Mondeos have, which is a misfire (normally at high revs) under load.

New plugs, leads, and plug gap less than the recommended gap solved it.

HTH

Pete.

It's the classic symptoms of a weak spark so I would tend to agree. If not, then ignition coil.

Well, the consensus for here and other forums was that this is an HT fault, so even though I thought the HT had been looked at sometime ago by our garage, I toodled off down this road.

I flipped off the distributor cap and there were some hefty build-ups on the contacts so I scrapped these off and cleaned them with a bit of fine sand paper and did the same for the rotor arm. No joy, in fact it seemed to make things worse!

So I went off an bought a new rotor arm and dizzy cap and installed, but only after making the basic mistake of pulling all the leads off and not remembering the firing order or rotor arm rotation (moppet). After this was looked up a a local garage opposite the motor factor's we back in business, but still with a misfire.

Therefore, that leaves plugs, leads and coil. I was sure that the leads were replaced by our garage but even so, I had limited tools with me to thought that that would be the next move. One set of leads latter (this time carefully replaced one at a time!) and bingo ? no more misfire.

It just goes to show that servicing does not always pay to be done a garage! Thanks for every one who suggested HT side of things. At least it has saved me the cost of an diagnosis at the Ford dealers next week.