I have an intermittent fault where my 2lt Mi seems to be running on 3 cylinders.

It has just started to happen and it can start at any time. It gets really lumpy and then smells of unburnt fuel. Anyone got any ideas, Cheers,

Stu

Have ya tried all the usual stuff like plugs, leads and dizzy????

Any loose connections????

Possible Coil problem?

It's a 2lt, so the plugs are under the rocker cover and the HT leads are just wires. On the top of the plugs are plastic things that look like relays.
As far as the dizzy is concerned i couldn't even see it after a quick glance.

I have probably caused some amusement to the engine guru's on here, but i'm fairly new to these engines, so any explanation of the above would be appreciated.

Cheers,

Stu

The plastic things on top of the plugs that look like relays are the coils, one for each plug. They sit on top of the plugs and are held down by the metal cover that bolts over the top. This traps in the heat, and the coils are extremely prone to burning out. I've lost 2 in the past 9 months, both times with symptoms just like yours. Also, there is no disributor.

You can get a new coil for around £40 from Euro Car Parts. Try ebay too, they are the same coils as on a 306 S16. Start the engine and let it warm up to the point that it starts firing on 3. Stop the engine and try replacing a coil then trying the engine again until ouy find the faulty one. You'll know which one because the engine will run properly.

I didnt bother putting the cover back on last time it happened to try and get a bit more airflow around the coils to aid cooling. I keep meaning to make some alloy brackets to hold them down but havent got around to it yet.

P Zero, you the man. This sounds like the problem and quite possibly the solution. And i've learned something new today.

Cheers,

Stu

also you could disconnect injectors (only the electrical connector i mean!)
one by one. you'll know which cylinder's coil is faulty as the engine will
continue running on 3 cylinders rather than 2.

or the easiest way, you could make a simple fault reader and get the info
of which coil is faulty (and if it's a coil at all) by connecting it to the diag port.

Cheers guys, i had to drive 20 miles back from work in it hoping it was going to make it, I had visions of my exhaust blowing up .

I'm going to try disconnecting each coil in turn to identify which one isn't working, and then swap it over to see if it's the coil or wiring.

I'm going to have to get a fault tester and check out what's the fault reading.

Cheers,

Stu

Changed the coil and it is working OK now, cheers for your help.

Stu