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Mondeo 1.8 Mk3 misfiring after new coil pack/leads/plugs

Hi all,

Bit of a technical question but I know there's a few on here who know their stuff so thought it was worth a pop...

My 2000 1.8 Mondeo started misfiring and was advised by roadside mechanic that it was almost certainly the coil pack. Replaced that with an OEM spec factors one and the problem went away but there was a small amount of hesitation at low revs that I put down to being coked up from running on 3 etc.

A few days later the problem came back. Changed HT leads, no joy. Changed plugs, still no joy, although running a bit cleaner after putting 3 of the original Ford leads back on.

Anyone got any ideas before I take it in to the garage?

Cheers,

TFC
Misfiring is usually an ignition problem but not always.
Change plugs anyway because they are cheap enough.
Damaged or faulty HT leads can be spotted by running engine with bonnet open in a dark garage.
Sparks or glowing will be visible on faulty leads.
To ensure all cylinders have a healthy spark remove each plug in turn, replace HT lead and rest plug on engine block.
Run the engine and a bright blue spark should be visible on plug electrodes..

Sounds like it could be an injector problem though, usually expensive items.
But try first running a bottle of injector cleaner through. (Redex etc)
Reply 2
Avatar for JC.
JC.
19
Original post by mphysical
Misfiring is usually an ignition problem but not always.
Change plugs anyway because they are cheap enough.
Damaged or faulty HT leads can be spotted by running engine with bonnet open in a dark garage.
Sparks or glowing will be visible on faulty leads.
To ensure all cylinders have a healthy spark remove each plug in turn, replace HT lead and rest plug on engine block.
Run the engine and a bright blue spark should be visible on plug electrodes..

Sounds like it could be an injector problem though, usually expensive items.
But try first running a bottle of injector cleaner through. (Redex etc)


I don't understand why people suggest this. It's such a mickey mouse way of testing when a pack of 4 inline spark testers that you can use again and again is only 8 quid.

Using these you can not only check the presence of spark, you can also compare the strength of the spark between each pot.
Original post by JC.
I don't understand why people suggest this. It's such a mickey mouse way of testing when a pack of 4 inline spark testers that you can use again and again is only 8 quid.

Using these you can not only check the presence of spark, you can also compare the strength of the spark between each pot.
Merely suggesting a way of cost free checking
Reply 4
Avatar for JC.
JC.
19
Original post by mphysical
Merely suggesting a way of cost free checking


At circa a tenner a proper set of testers pay for themselves in time.
You wouldn't advocate using a butter knife in lieu of a screwdriver!
Reply 5
Avatar for Walkaah
Walkaah
11
I had a misfiring problem recently with my VW Polo. I first replaced one of the 4 coils and the problem still existed however it wasn't as severe. Turned out after replacing a few other bits and bobs that didn't make a difference either. Eventually took it into the garage and it turns out 2 of the 4 coils went at EXACTLY the same time which was causing it. Maybe the same has happened to you?
Reply 6
Avatar for dhr90
dhr90
18
Original post by JC.
At circa a tenner a proper set of testers pay for themselves in time.
You wouldn't advocate using a butter knife in lieu of a screwdriver!


Wait, you don't use screwdrivers to spread butter? Maybe it is just me then... :tongue:

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