Topic

There's been a bad misfire on mine since I got it. I've not driven it much whilst I've been doing the interior and a few other jobs but need to press on and sort the way it runs.

Changing the air and filters hasnt made any difference. It idles fine and will chug along at urban speeds ok but sounds like an asmathic tractor as soon as its under load, any gradients etc. My first thought is to check the HT side but I'm used to fault finding on older cars with a single coil and accessible spark plugs. Not sure where to start with the coil packs and buried plugs on this. What's the sequence for checking the state of the TF's ignition please ?

Sounds like the ignition breaking down.
Start at the plugs and work your way back.

Will do. I've ordered a set of plugs from mgfntfbitz and spotted a 2nd hand pair of coils on there that were too much of a bargain to miss. They didn't have any leads in stock so just ordered a pair of Lucas branded leads from a motor factors. That should give me enough to fix/ rule out any problems with the ignition I'm hoping

Any tips on how to remove the coil packs. I've removed the bolts and disconnected from their feeds and external HT leads but I'm not sure how hard i should pull them upwards to disengage them from the plugs beneath. Can I use something to gently lever them upwards ?

Just pull as much as required to get it done, if it breaks it needed replacing anyway

The usual issue is the rubber boot sticks to the spark plug. Twisting while pulling might help...
Corrosion between the coil and the spring can cause uneven running.

If moisture has gotten in there then that’s likely the cause of your woes and also probably explains any great difficulties in removing them, like I said before if they break they were probably not working anyway.

When I had the tf I replaced all that clutter & it transformed the car. The Mk1 f has the coil pack bolted on the back of the engine, under the inlet manifold, with looong plug leads, I’d rather change your system than mine.

With the coil packs tucked up under the inlet manifold with poor ventilation and the confined engine bay no wonder the coil packs overheated on those models so equipped

I thought the misfire was noticeably far worse than before and just realised why. Removing the #4 spark plug lead revealed its recess was full of clean oil. I'm guessing the spark will have dissipated into the oil rather than into the plug but then wondered why it was quite as bad as this because on the short trip the engine felt at times more like it was running on 2 cylinders than 3. I'd not experienced anything running quite so badly due to a single cylinder misfire. Then I realised im used to distributor based ignitions and what im seeing here is a consequence of the wasted spark system. The same coil pack provides a simultaneous spark output to 2 cylinders so presumably when one side is wrongly earthing out then there wont be much of a spark at all at the other plug either ( Does this sound logical).

The one thing i do know is how the oil came to be there. The funnel slipped when refilling after the oil and filter change i did last week. At the time I'd thought I'd sucessfully managed to mop it all up with rags and like an idiot didnt think about any finding its way under the cover and depositing itself into the nearest spark plug well ( which #4 is).
Having already ordered new plugs, leads and coil packs il wait til they arrive then change the lot and hopefully it should then run perfectly. Can't wait to start using the TF a bit especially now the weather is improving

Yeah a gut full of oil will do that!

Ah, the oil cooled spark plugs modification!