nick-21

My standard mk2 1.8 mondeo has issues! The acceleration is quite often lumpy, this can be while at steady speed and you can feel it jerking, when you put your foot down it is very prominant. There also feels like it has lost some power over all, its not what it used to be? (not that there was very much to start with)

What is this most likely to be, injectors?

Cheers Nick

stevetinks

most likely the MAF sensor needs a clean

tabetha

As said would not hurt to clean the maf, look also for signs of corona discharge/leaks on the plugs, or if using BOSCH take them out an bin them.
tabetha

Dangerous Malcolm..

When were the plugs and leads last changed? When was it last serviced?

nick-21

Was last serviced just over a year ago, so just over 8000 miles. An no idea when the leads or plugs were changed, will check plugs 2moro evening then.

tabetha

I put 4 new plugs BOSCH in my mondeo, ok to start with but less than 100miles later TWO of them were arcing like f**K, leaking up the side of the plug, I had 10mm Kerr Nelson leads on as well, swapped to Motorcraft, been perfect for three years now.
You look for greyish streaks up the side of the porcelain on the plug, a "stain" around the base is normal, and light brown in colour don't worry.
tabetha

nick-21

Yeah it is bosch ones that are in there, got the day off work 2moro so ill have a proper look at the plugs then. Cleaning the MAF sensor did not cure the problem, was hoping for once it would be a quick fix job!

nick-21

Well i pulled out the plugs, all bosch. Two looked worse as in more dirt on them, so swapped their posistions, ie clean ones where the dirty ones were and everything now runs smoothly, the power is back and no jerking. So does this mean ive got 2 dodgy leads meaning the spark plugs arnt sparking properly so when they get dirty from this they dont spark properly at all?

Dangerous Malcolm..

Get some new plugs and leads on, it's probably only a temporary reprieve.

tabetha

It means you have dodgy plugs, bin them.
I would use Motorcraft plugs, the ones that were th dodgy postions will become dodgy again as the "new" ones start to leak in that position.
This is caused by amongst other things oil mist, so fine you can't see, this forms a path for the electricity to leak out from between the plug cap and porcelain part of the plug, this is why FORD use SILICONE on the plug lead ends inside the cap, this is a VERY known problem, sometimes just wiggling the cap will cure it for a few miles.
For some reason BOSCH plugs are much worse, most likely due to a higher resistance than the ford ones.
tabetha