Ford Focus misfire

[JasonF]

Hello all
I have Ford Focus 2002 1.4 its started to have slight misfire when engine is warm and only when changing up gear at low revs, it stutters. I've changed the coil but still no better its still got the original ht leads on. I'm thinking now that when the engine is hot the leads which are old are breaking down, it had new plugs last year. It doesn't misfire when parked and has a good spark from all ht leads. Any suggestions will be gratefully recieved.

Thanks to all

Jason

 

[Nige F]

16 year old HT leads have got to be worth changing

 

[Mottie]

They should be changed around the same time as the plug leads - every 30k or 3 years. It’ll cost less than £20 to change them.

 

[jj4091]

Is there any oil on the ends of the plug leads or are they wet when you pull them off the plug? Also if you shine a torch down into the plug well is there any obvious oil or water? If so could be either rocker box gasket leaking oil or core plugs leaking water.

 

[JasonF]

Had a look today bone dry thanks anyhow any other ideas

 

[Mottie]

Did you replace the HT leads? Check the connections at the multi-plug on the coil pack. They sometimes corrode or loosen up. You can get repair kits if needed off of eBay for a tenner.
https://www.ebay.co.uk/itm/Ford-Foc...011272&hash=item4b444ad2d0:g:WZkAAOSwL7VWmzn0

 

[JasonF]

Did you replace the HT leads? Check the connections at the multi-plug on the coil pack. They sometimes corrode or loosen up. You can get repair kits if needed off of eBay for a tenner.
https://www.ebay.co.uk/itm/Ford-Foc...011272&hash=item4b444ad2d0:g:WZkAAOSwL7VWmzn0

Replaced ht leads today, problem solved, £23 for Bosch, shame I spent £35 on a new coil but still worked out cheaper than a garage. Thanks for the advice

 

[fixitflav]

Hello all
I have Ford Focus 2002 1.4 its started to have slight misfire when engine is warm and only when changing up gear at low revs, it stutters. I've changed the coil but still no better its still got the original ht leads on. I'm thinking now that when the engine is hot the leads which are old are breaking down, it had new plugs last year. It doesn't misfire when parked and has a good spark from all ht leads. Any suggestions will be gratefully recieved.

Thanks to all

Jason

I had same thing on a 2004 Mondeo. A website suggested HT leads or coil. HT leads slightly cheaper so did that first - no improvement. Changed the coil, that cured it.