Hi All

Again, working on the other halfs Mundano and to my mind it is missfiring...

It ticks over ok, and drives OKish, but there is definitely something not right with it. It judders and lurches under acceleration, sometimes only a little, othertimes badly (light if you plant your right foot it feels like it will stall so have to lift off again).

Anyone have any ideas what it may be as I am at a loss!

One suggestion I have had is get it plugged into a fault finder, but I really cannot afford to pay maindealer prices

Thanks

Mark

It could be the coil ISTR that they do brake down.
I would take it to an independant garage if you have one local and ask them to do the diagnostics the Mondeo will be OBDII compliant and I would guess that most Indies have the diagnostic kit to check it.

I had the same problem on my escort after an engine service last year, after a bit of fiddling i found one of the plug leads was failing. Managed to catch it running lumpy with the bonnet up, when i pressed down on the leads into the head one of them made a significant difference and i found it just wasnt snapping onto the plug properly. Changed the one lead and all was ok, i think i might have damaged the lead myself when removing to change the plugs as they are sometimes a bugger to get out.

could be a dodgy throttle potentiometer. that would give the symptoms you describe

I would check the following (in this order)

Leads/plugs
Coil
MAF

EGR valve blocked, crankcase breather valve blocked?

Agree with Steve - definitely in that order.

Most parts can be sourced cheap from breakers yards... HT Leads are expensive and are not commonly sold singularly - so nip down to the breakers and grab some cheap. Even if they aren't the cause, you can sell them again...

Just had a knackered coil on a 2.0l focus giving a weak spark on 1 and weak to no spark on 4.

I removed each lead from the plug one at a time while the car was running.

You could clearly hear it arcing on 2 and 3 and a little on 1 but next to nothing on 4. Removing the lead from 4 hardly effected the running of the car.

This is the quickest way to narrow it down to a cylinder, when removing a lead that has little effect on the running of the car you know which cylinder the fault lies with, or cylinders.


Steve

If you try pulling off the HT leads as above make sure you use a pair of insulated pliers preferably plug lead pliers. 40,000+ volts gives a bit of a shock!

Plugs + Plug leads
Coil unit

Fuel pump/filter

Fords use a massive plug gap which can cause a lot of ht problems this is not helped by the extended plug change intervals now specified, if the plugs are flailing it is usually best to fit plug leads as well to fit plug leads as well.

I find setting the gaps to a lower figure than the Ford recommended leads to fewer problems later down the line.

Thanks for all of the advice guys

I tried the pulling the plug leads off trick and strangely there was no change at all when I removed the lead from cylinder 3...

I have already fitted new plugs last weekend (or was it the weekend before?) which didn't help so the leads look like a very good place to try next!

Thansk

Mark

Hi All

Thanks again for the advice, it did turn out to be the HT leads. The car runs sooooo much better now!

All I have left now is the to fix the rattling exhaust and why the (new) temp sender isn't working, but they are minor (i.e. I don't have to buy her a new car )

Mark

Its a nice feeling when you can sort a problem for not so many £££'s

Pleased for you,

If your like me you always think the worst and it rarely is that bad.

Steve