Car juddering in 5th on dual carrige way

[Jakus]

sorry what do you mean close the gap 25%?

ive just brought some WD the other day so will give them a squirt

You are not the first A spark plug had an adjustable gap between the central electrode and a little bent earth tab, this tab is carefully bent to adjust the air gap to manufactures specifications.

Old engines used to use gaps of around 25 thousands of an inch about 0.6mm the electrode and earth was said to erode away about .001" per 1000 miles in a healthy engine, so it the plugs had been it 25000 miles the gap could be now 50 thou .050" (1.2mm).

Modern plugs are better materials with many precious metal electrodes so they will not erode as fast but still they will erode.

Old plugs and big gaps require higher voltage to make a spark jump the gap, if you reduce that gap the voltage will be reduced so also less likely to be jumping through a lead or plug cap which is possibly your missfire.

http://www.youtube.com/watch?v=lk70oyUEftY

Don't worry we use different feeler gauges blades rather than wire generally but it will give you the idea.

 

[Hagar]

You are not the first A spark plug had an adjustable gap between the central electrode and a little bent earth tab, this tab is carefully bent to adjust the air gap to manufactures specifications.

Old engines used to use gaps of around 25 thousands of an inch about 0.6mm the electrode and earth was said to erode away about .001" per 1000 miles in a healthy engine, so it the plugs had been it 25000 miles the gap could be now 50 thou .050" (1.2mm).

Modern plugs are better materials with many precious metal electrodes so they will not erode as fast but still they will erode.

Old plugs and big gaps require higher voltage to make a spark jump the gap, if you reduce that gap the voltage will be reduced so also less likely to be jumping through a lead or plug cap which is possibly your missfire.

http://www.youtube.com/watch?v=lk70oyUEftY

Don't worry we use different feeler gauges blades rather than wire generally but it will give you the idea.

This will also tell you if the mixture is about right. A black sooty plug is either rich or misfiring, a gold brown colour is about right and white or light brown signiifes a weak mixture.

Using a feeler gauge, first pull some emery paper through the gap to clean, then with the gauge in, gently tap the outer electrode with the handle of a screwdriver until the gauge just slides without being overtight.

 

[mattyfez]

how did you find out it was the lambda sensor?

Owners forum... worth its weight in gold, as if id have taken it to a garage, they would have replaced plugs leads, coil pack blah blah and I'd still have had a problem.

Every one on the forum was like, I bet you its the lambda, they always go.. so I took a chance and it worked. I cant guarantee that's your issue as its a different engine, but something to consider.

 

[Dis86]

I'd agree with matty and check it out too. Symptoms make sense.

 

[Tom_ed1987]

ECU goes into open loop when you plant your foot, therefore faulty lambda wouldn't prevent the car from accelerating as normal. Lambda sensors are easy to test anyway with a simple multimeter - i'm sure a howto can be found on Google. My money would be on faulty ignition components.

 

[bledd]

It's a Ford Fiesta.

NGK plugs will be about £2 each, just replace them, don't bother messing with them.

I'd replace all filters/plugs/fluids on the car. Good idea for any second hand car with unknown history.

If the problem still exists, check all hoses for air leaks and go from there.


-Also, might be worth checking, has the cambelt been done on this. As it's overdue if not..

 

[FatFishMonster]

It's a Ford Fiesta.

NGK plugs will be about £2 each, just replace them, don't bother messing with them.

I'd replace all filters/plugs/fluids on the car. Good idea for any second hand car with unknown history.

If the problem still exists, check all hoses for air leaks and go from there.


-Also, might be worth checking, has the cambelt been done on this. As it's overdue if not..

thats the plan for pay day next week
new filters, new oil, new plugs
and new ht leads if i can find some that fit my car, so far been unsuccessful in my search!

 

[Stuff]

Had this recently on my old Astra - The coil pack needed replacing, cost me about £130 including labour.

 

[Fr0dders]

think its the engine, could be gearbox.
its not the wheels, it pulls fine after a bit a juddering, its not a violent juddering, i.e my passengers dont notice it, but as im the driver i can tell, the steering it perfectly fine while juddering, just the less power from the engine it feels.
theres no engine check light come on.

when it happened yesterday, i assumed it could be just the cold weather.

The car is misfiring

most likely an coil pack or spark plus as already suggested.. I know some are very handy on here, but you don't sound the most confident at changing stuff yourself, so just get it booked into a garage

 

[FatFishMonster]

The car is misfiring

most likely an coil pack or spark plus as already suggested.. I know some are very handy on here, but you don't sound the most confident at changing stuff yourself, so just get it booked into a garage

my friend is a mechanic, he will be doing it for me free of charge, whilst at the same time giving me a few pointers on doing certain things myself in the future