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

Hi,

This problem has been bugging me for ages. I have a 1.8 CVH that exhibits a misfire problem and high load conditions at low revs. (E,g pulling up a steep hill in second, or even just flooring it in third with the engine at about 1500 rpm). It's like the advance is way off - but of course there is no manual adjustment of the advance. Releaseing the throttle and reapplying sometimes clears the problem and when she picks up she flys (as best a 1.8 CVH can fly!)

I have bypased the fuel seperator, chnaged the ECS module and crank sensor (albiet with second hand parts), checked it over on some crypton tunning kit (which checks out fine), even changed the fuel pump push rod.

Anyone have any ideas?

The car has inetermitantly died on us a few time in the past as though all electrics went, only to be able to start some 10 minutes later, but this hasn't happened for a while - possibly through one on the changes mentioned above.

Reply to
Swinster
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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).

Reply to
Carl Bowman

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.

Reply to
Pete Smith

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

Reply to
SteveB

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.

Reply to
Swinster

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