P38 won't idle hot and ht lead arcing

Right I've got a 4.6 and it won't idle when it's warm, fine when it's just started from cold. It's the same on gas and petrol. I recently changed the plugs and it started soon but not straight after. Now I don't know if this is the cause or a separate problem but whilst underneath the bonnet I could see a spark jumping from one of the ht leads on the coilpack, to a red/brown piece of plastic next to or part of the coil pack, it looks a bit like a circuitboard made of layers!!?? Would this cause the none idle?
I'm presuming i need to change the ht leads but how the he'll do you get to them?

Thanks for your help mike

you may need a coil pack as well. tis common for coil to burn out..

4.6 ? what year? if its the gems then its a straight bank of eight at the bulk heat bolted to the engine, if its thor then you will need to start feeling each lead and replace one at a time to make sure you get it right!!!

gavbriggs said:

4.6 ? what year? if its the gems then its a straight bank of eight at the bulk heat bolted to the engine, if its thor then you will need to start feeling each lead and replace one at a time to make sure you get it right!!!

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hello stranger,how are you matey.

Oh great I feel more expense coming on! Haha

It's on a p plate. It looks like it's got two packs of four if that makes sense, but saying that there's so much room to see in that area it could be anything. Do you have to take the plenum off to do it?? Or is it the plastic thing under the windscreen?

Cheers for replying

.

hey up john, im fine ta, hows u?

the two packs of 4 are the thor type arent they lads?

you will have to take the plenum off i think to gain access to change em!!

I thinks its 4 packs of 2 being a p reg

Well I've just been and bought some leads for it as I've noticed another lead arcing to a hose next to it. Fingers crossed

Seems luck isn't on my side with this car! New leads in and it still won't idle. Fine when cold but when it's hot no chance. Runs great though other than that.

does the engine have an earth strap on this car/engine?

Don't know to be honest mate.

As the leads are new, sounds like shot coil to me...
Pinch another one for testing.

Before you start jumping around, you need to sort out any shorts or tracking on the HT side. Get that right and then you can move on to the next step in the process of elimination. Could well be a coil breakdown issue. Being a "P" reg and petrol narrows it down to a GEMS. If you can get a coil pack (s) on a sale or return basis, swap them out and see if there is any difference

Automania said:

Seems luck isn't on my side with this car! New leads in and it still won't idle. Fine when cold but when it's hot no chance. Runs great though other than that.

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Faulty coolant temperature sensor for the engine ecu ????..Part no. ETC8496

Yeah the arcing seems sorted now. Where I get my spares from has also said it could be the coil packs so think I'll get some of them.

Would the sensor make a difference? Is there any way of testing it before I replace it?

Thanks mike

You're talking about a fiver for an aftermarket sensor. Replacement is a bit like the boy with his finger in the dyke. Have the new one handy, together with sealing washer, whip the old one out and pop the new one straight in, you will lose about a tablespoonful of coolant if you are quick. I suffer from alcoholic shakes and dementia, can't remember where the new sensor is so if I were doing the job, about 1/2 pint of coolant would be lost...better than spilling the equivalent amount of beer I must admit.

Irishrover said:

You're talking about a fiver for an aftermarket sensor. Replacement is a bit like the boy with his finger in the dyke. Have the new one handy, together with sealing washer, whip the old one out and pop the new one straight in, you will lose about a tablespoonful of coolant if you are quick. I suffer from alcoholic shakes and dementia, can't remember where the new sensor is so if I were doing the job, about 1/2 pint of coolant would be lost...better than spilling the equivalent amount of beer I must admit.

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How bout puttin the beer down for a sec while you swap the sensors? Just a thought...

philvy said:

How bout puttin the beer down for a sec while you swap the sensors? Just a thought...

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I am a senile old grumpy git who can't handle multi tasking.
I joined this forum by mistake a few years ago after reading a post about "Little End" problems and do't know how to delete it from my favourites toolbar.

:beer2::beer2::beer2::beer2:

Irishrover said:

I am a senile old grumpy git who can't handle multi tasking.
I joined this forum by mistake a few years ago after reading a post about "Little End" problems and do't know how to delete it from my favourites toolbar.

:beer2::beer2::beer2::beer2:

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And the three thousand and so "posts" are "pints" in you case i assume?