Spark Plugs, HT Leads, Coilpacks and Headaches!

Member 55145

Distinguished Member
Ok ok, as i cannot find the answer ANYWHERE on the internet.
I changed the Sparks and HT leads on my wifes MK2 mondeo the other day as her car was due a service. I swapped the leads one by one and believe I did it correct.
I noticed there was a pattern that if the engine cylinders were ordered from left to right as cylinder 1,2,3,4 then cylinder 1 went to coil pack 1, cylinder 2 went to coil pack 2.... etc etc (Why does nowhere say where cylinder 2 is to stop confusion?)

Anyway before starting her Engine I thought I would look at my Engine in my MK1 Mondeo to make sure I had done it right.
Anyway to my horror it was different! and didnt make any sense whatsoever

If my asumption of cylinders were correct then
cylinder 1 was going to cp 1
c2 to cp3
c3 to cp2
c4 to cp4
:eek: not making sense but i know my car works!

to make matters worse I went and looked at my trusty Haynes Manual and Ford owners book and all they said was
"The firing order is 1-3-4-2 and 1 is at the timing belt end" no diagrams or anything!

So what the hell is the firing order? is that the pack firing order or the order the cylinders fire in or what? the only helpful hint the Haynes manual said was "Be sure to mark or take off the HT Leads one by one to avoid mixing them up!" how useless is that for someone who thinks they have gone wrong! is it that hard for an instruction manual to give you instructions!

having read up on engines a few years ago the basics i grasped were that distributors go around in a clockwise circle and fire the spark plugs and that an engine has a 4 stroke cycle meaning that cylinder 1 goes then 3 goes then 2 goes then 4 goes keeping the engine nice and balanced.

So does the coil pack also go clockwise being 1324. or does it go, top left, top right, bottom left, bottom right giving me 1342 (giving me my firing order?)

anyway lets stop and get to the crunch of this. is my diagram correct? I came accross a website which writing this that fortunately explained how 4 cylinder engines work.
Basically an engine to remain balanced has to fire
an outer port (1 or 4)
then an inner port (2 or 3)
then the other outer port (say port 4 if port 1 went in step 1)
then the other inner port (port port 3 if port 2 went in step 2)
then the cycle repeats on port 1

So this means either car is set up correct even tho they are set up differently (and would explain why the engine even worked when i tried labling cylinders 1234 from right to left!)

anyway can someone please end my circle of confusion? all i know is the engine on the mk2 rattles unlike my mk1 and the exhaust pops (which it was doing before the change) and that a mechanic who couldnt help me with the firing order said it sounds like its misfiring :rolleyes: (lot of use that idiot was i tell you!)

thanks for helping if you can!
 

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SeanT

Distinguished Member
It's a wasted spark system (and is the same EDIS 4 system on both cars) - 1 and 4 go to one side of the pack, 2 and 3 to the other, doesn't matter which way round these go - explanation here including which side is which - Minifinity.com • View topic - EDIS coil pack firing order

If you make sure that both coil packs are in the same orientation when comparing, and they are connected the same, this should be fine - you should be able to swap the coil pack itself from one car to the other with relative ease, to prove this bit.

Sounds like you have another problem basically - is there any smoke from the mk 2?
 

Member 55145

Distinguished Member
no smoke but the exhaust has a black ring and the cylinder 4 spark plug was darker than the others. Also when disconnecting spark 4 the engine runs the same but taking of any other and it runs bad. So I'm thinking there's a problem related to cylinder 4
 

DVD-Man

Well-known Member
Year and engine size will help us help you.

I can take a pictue of my Focus Engine bay for you should be the same, 99 2.0.

Liam
 

Member 55145

Distinguished Member
Year and engine size will help us help you.

I can take a pictue of my Focus Engine bay for you should be the same, 99 2.0.

Liam
98 and 1.8

Is the plug sparking if you put the lead on it and earth it against the head? Also do a compression test.
earth against what head? also dont know what a compression test is.

is anyone able to tell me how the ht leads are supposed to go?
 

DVD-Man

Well-known Member
Here is the picture



You count the cylinders from left to right so 1,2,3,4

When you changed the leads and plugs where did the parts come from? Genuine Ford stuff?

No offence meant but I think your not too sure about cars so shouldn't really be changing these bits.

Were the plugs all gapped etc?

Hope this helps

Liam
 

Member 55145

Distinguished Member
HT leads were CI (Not ford) and apparently are used alot. and got NGK platinum plugs which are gapped at 1.0

tried putting one of the motorsport plugs back on cylinder 4 and made no difference
 
unscrew no.4 plug, put it inside the lead, hold the rubber head of the lead and touch the thread of the plug against a metal part of the engine and have a friend start it and look for a spark. dont zap yourself. if its sparking check fuel is coming through, and if fuel is coming through do a compression test. without knowing whats causing the miss you`ll just waste endless money trying to fix it.

Or have someone who knows about engines have a look at it.

Did you service it because it was misfiring, or is it misfiring because you serviced it?
 
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