Hi all
Still having problems with my 2.0 zetec.
Its running Megasquirt which has had a new wiring loom fitted now it has blown 2 coil packs.
( I say blown both times they have fun fine for a couple of miles then started running on 2 & 3 only)

Any ideas what this could be cousing this?

I changed the plugs and leads before the coil packs if that helps at all

The megasquirt switches the negative side, you only have 1 12v feed to both coils, so its unlikely the ms.

Where are your coils mounted? close to a heat source?

Have you checked all the wiring for chafing and shorting?

Which side of the coil has blow 12v or ht, you can check the continuity of the 12v side pin 1-3 and 2-3 should show the same impedence, similarly ht 1-4 and 2-3

Sounds like a high dwell setting are you running edis or coil drivers in the Ms ?

Yep check the 'coil on time' if you can and reduce it. It's adjustable on the Emerald I have.

lower the dwell on it, those coil packs really don't handle high dwell times. if you go on msefi.com im sure you will find the recommended dwell settings for your coil.

The very wide plug gaps specified by Ford don't help --- they cause excessive HT voltage

[Edited on 25/8/10 by britishtrident]

Fords did specify 1.3mm gap for plugs in the early days but changed it to 1.0mm. That was due to killing coil packs with the big gap.

Check the coil packs aren't left in a "live state" if the ignition gets left on etc.

I changed ours (or it should have been in the first place) to run from the fuel pump relay so its only live when the engine is cranking and running so it isin't left sat there in its "charged" state