Hi all am new just wondered if anyone can give me pointers am going to look a ford focus 1.4 CL the car has a misfire on acceleration it has done 176k miles lots of service history. Am not really clued up on ford's could I be buying big problems or a cheap fix. apart from the misfire is there anything else I should look for sorry about the questions.

Hi

First thing i would check is the condition of the ignition leads.

If they appear cracked or worn replace them.

If you have extensive service history check when the Spark Plugs were changed.

If they have not been changed for a couple of years consider changing those too.

I Must warn that a continuous Misfire could Lead to the Failure of the Catalytic Converter.

Hope this helps

Jamie

Hi took the plunge and bought the car very cheap after haggling herdown so if it turns out to be a major problem I'll just scrap it only been used as a second car. OK the car starts off the key no problems the Idle is very lumpy and does stall occasionally.the misfire is there all the time regardless of rev range also notice black/grey smoke on start up the dispels after a few seconds but if you rev it you get alot of black smoke but no blue smoke? The ignition leads look ok coil pack looks new so quite stumped the previous Owner said the car was driving fine the lost power and started misfiring so had towed back to her house. And bought a new car? And not really looked at so any pointers what may be causing the issue would be greatful. Sorry for long post rich

Also no warning lights on dash board and no fault codes stored thansk

Black smoke is indicative that the engine is running rich - take the spark plugs out & inspect - they should be an even tan colour - if they are black there's a fuelling / air imbalance

Blue smoke is indicative of the engine is burning oil - not unusual at that mileage, but could lead to issues if the blue smoke is excessive & constant

Tha ks for reply There's no blue smoke it was revved high at cold start but only got black smoke with a puff of grey on initial start. it's been oil changed every 5000 miles got a whole folder of service history so it's been very well maintained car. More black smoke then grey so what could be causing rich running and misfire

Take the spark plugs out & see what colour the tips are

Just looked at plugs there ngk r plugs don't look that old there a light tan colour at the ends that go into the cylinders

The colour is good then.

I do know from very recent experience that some Ford engines do not like NGK spark plugs

Hi If the rest of the car is good dont scrap it just because of a few running problems

check also the air filter etc

Jamie

As above - check the air filter & google '' petrol engine black smoke '' for pointers on why your engine is probably running rich - hence the black smoke, which is often too much fuel & not enough air in the combustion chamber.

The NGK plugs could also be an issue

Cheers all yeah car is in great nick been very well looked after just got a feeling it's a sensor or vaccum hose but no idea of location or ones that usually pack up again thankyou 👍

Or which sensors would cause a continual misfire

A misfire can be caused by a failing coil pack or packs - just because '' they look ok '' - does not mean they are ok - & testing at a garage will prove it either way

Thanks will get it checked out

So this afternoon borrowed a coil pack from a friend who's car is working perfect btw same car engine differt spec. there's no change to engine. Changed plugs to bosch ones and new ht leads slight change but still running rough through out rev range also noticed there is a variable popping noise coming from the airbox intake hose any ideas what can cause this thanks

Is there a M.A.F. ( Mass Air Flow ) sensor on this car ?

If there is, it may or may not be serviceable, maybe take it out & clean it VERY CAREFULLY with electrical contact cleaner

Did you check the air filter ?

Air filter ok. I've just been searching through the interweb and came across a few articles which tell you to disconnect the MAF sensor with engine running see if it makes a difference to running. I've just tried it and it makes no difference also it doesn't throw the orange EML light on which it said it should. the EML light is working as it comes on when ignition on and goes out when started very strange btw thanks for replys and info👍

Could be a dodgy MAF sensor by the sounds of it

Would that cause the constant misfire?

It may or may not be directly linked, and certainly is not helping, but in any case it needs fixing.

Just an update had compression test done today and results are 220, 218, 220, 220 No2 down a bit would this cause the misfire

those readings are really good and no they would not cause a misfire

Has the car had a cambelt change. is the valve timing correct.

when you say misfire how bad is it.

Can you do a youtube video ??

Jamie

just an afterthought

Has the fuel filter been changed

would running through a fuel injector cleaner help

Jamie