Took the car out to go to Newlands this morning, It's not running on all cylinders.

With a suspect head gasket or dropped piston ring as there was oil/fuel mixture coming out of the exhaust gasket, we(cheers Cheffy), whipped the head off and had a look, The bores are pristine and there was no obvious tracks across the head gasket to indicate a failure.
Managed to limp the car home and stuck the laptop on it to see if the Megajolt was running in limp home mode, No all happy on that front, did a cont check on the coil A&B wires all good, removed the spark plugs and held them against the block, No1 has a nice fat spask, No2,3&4 well were pants. Swapped the coil pack for another and the problem didn't clear.

So, am i unlucky enough to have 3 HT leads fail or the spare coil pack U/S aswell, or does anyone else have any other ideas?

ATB Dan.

P.s. This zetec can't come quickly enough

I,ve seen a complete set of HT leads being pants.

Does the fat spark follow the good lead ?

Maybe the EDIS module or the coil drivers have given up the ghost, although you would have though that would knock out a pair of coils and not 3!

The coils are paired, so unless you're getting two good and two shite, I'd be inclined to think HT leads have gone west if you've got one good spark on one side of the coil, and one bad spark on the other.

HT leads do exhibit some fecking odd failure modes. As suggested, swap the lead with the good spark to another coil post, and best you a pound to a pinch of poop that the good spark follws it. If you've got a multimeter, do a resistance test too.

Does anyone have off the top of there head what the HT lead resistance should be?

ATB Dan.

No, sorry, but check the good lead, then see if the others are the same ???

Jason

I like your thinking young man

ATB Dan.

Hi Dan, from experience HT leads usually measure in the 5k-15k ohms range, depending on how long they are. I've found that if they're duff they'll normally measure much higher than this, probably open circuit. You're right to be suspicious of them, they can cause loads of problems, easily checked with a meter though.

Good luck! Geoff.

Ok, let this be a lesson on back to basic and curing the fault not the symptom.

Got a relpacement set of leads today(nasty things as it turns out but they're going back)still the same problem, I'd brought new plugs at the same time and procceded to fit these, result a nice runnig engine, refitted the old leads and still a nice running engine.

I then took out the new plugs, wet and slightly black after 5 mins of running, as were not using any oil and the car had to moved out of the garage for the build up of fumes was so bad, I think the engine maybe running slightly rich.

So as a lesson, i think a little assumed knowledge on my behalf is a bad thing and as many moons ago i'm sure i learnt all this in basic engineering, I stand guilt of looking to deep into things

Now, where's the nearest rolling road that understands megajoly/dellortos?

ATB Dan.

Northampton Motorsport did my dellortos and Megajolt on my XE. I've got an MS now and I can see how well it ran on carbs - I was happy before but comparing shows it even more.