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Mike, Technician
Category: UK Ford
Satisfied Customers: 39198
Experience:  34 years experience of motor vehicle diagnostics
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Ford Focus LX 2005 focus 1.6 petrol engine starts from cold

Customer Question

2005 focus 1.6 petrol engine starts from cold runs for aproxamatly a minute then starts missing hand stops , will not start again for about an hour , no codes present and have changed leads, coil pack , air flow sensor, battery, any ideas ?
Submitted: 6 years ago.
Category: UK Ford
Expert:  Mike replied 6 years ago.


Hello and Welcome to justanswer....

JACUSTOMER-9ud3d147- : Hi do you have a diagnosis

Hello.. I need a few more details first...


What is the mileage on the car - and what is its service / recent repair history...?


...apart from the parts you have listed ..

JACUSTOMER-9ud3d147- : The car has done 30000 miles only and it was running fine but we changed the plugs and gave it a oil and filter change and now it will start from cold and run for a while but as soon as you let your foot ofmthe gas it stops and won't start again , once it starts getting warm it starts to misfire and wont rev up properly , the carbis a 56 plate

so these probems have come about since what you did ??

JACUSTOMER-9ud3d147- : Yes

Exactly what type and grade of oil did you use?

JACUSTOMER-9ud3d147- : Whatever the manufacturer recomendations are
JACUSTOMER-9ud3d147- : It was 5/30

ok - so long as it was - because that is important. and especially as this has only happend since what you did ...


are you sure the level is correct - not overfilled... and too - importantly, that the plugs are the correct ones ( there are different ones ) and that they are gapped correct...



JACUSTOMER-9ud3d147- : Yes oil level correct and have changed plugs again just to make sure

to th old ones?



JACUSTOMER-9ud3d147- : Yes and more new ones

ok - does the EML - engine management light come on when its running?

JACUSTOMER-9ud3d147- : It has done once or twice but when scanned just says multiple misfire

ah.. what codes do you get?



JACUSTOMER-9ud3d147- : Random misfire p0300

ok - have you identified which cylinders are missing... ?

JACUSTOMER-9ud3d147- : It runs on all 4 fine but son as starts to get warm it starts to miss and dies ! Doesn't give enough time to identify

right good we are getting there then... two things... Disconnect the air flow meter that you have fitted - ( the wiring connector..) and see how it is then.. If it runs ok - then you have a faulty AFM - even though new ( it does happen )... Second - if its not that - such symptoms are indicative of an inlet air leak....and this is often caused by a split / persihed pipe or one that isn't fitting correctly - loose etc.... so you need to check all these , especially small bore pipes... and too - check the vacuum pipe where it connectrs to the manifold for the brake servo.....

JACUSTOMER-9ud3d147- : Just been informed we have changed crank sensor swell and apparently when you turn ignition on to start it the headlights flash

The situation you describe is often caused by such a leak - and inlet leak evern a very slight one - or a faulty AFM as mentioned.


( the headlights flashing is alarm related - if you find you cannot cure this as above... you need to have that checked out - for that you will need more than a fcr machine ( fault code ) you will need it plugging into a genuine Ford machine...


so work through as above...and check the elctrical connections etc as well to the sensors etc - but do that with the AFm - first - and then work on as above. One way or the other as above , you will find the fault that way.


Can I help you anymore at all ?

JACUSTOMER-9ud3d147- : They have checked all pipes for leakage and checked all connections so I would say it now has to go to fords
JACUSTOMER-9ud3d147- : There is good fuel pressure too , we have disconnected battery for 30 mins

Ok - well more in depth diagnostics will find it as I say - It could well be a sensor fault that has coincidently developed as you did the job - but be sure that they have indeed done all the checks as above first... Re the fuel pressure - that needs testing while running - continuouly - but that can be done with Ford equipment electronically ( within the diagnostic testings )..

JACUSTOMER-9ud3d147- : Could it be ecu

Yes its possible - thats why I was asking about narrowing it down to a miss... if the ecu is at fault - it will usually give two cylinders down.


If thats the case though - you generally get two dead cylinders ( no spark ) at all ...

JACUSTOMER-9ud3d147- : No all four are firing until warm ! Well I've never had one like this before so think will have to go to ford

ok thats what I was deducing - which is why I was going down the lack of vacuum line of thought - What mileage does it have?

JACUSTOMER-9ud3d147- : 30000

30... ?

JACUSTOMER-9ud3d147- : Yes

Ok - you need to have the testing done as above... could well be a fuel pump fault - These did suffer with these - and just FYI....if it turns out to be that - Fords were replacing a lot of these FOC even on older they were a common fault. Im telling you that just in case.... it they say its that - mention that too them !

JACUSTOMER-9ud3d147- : Ok will do and thanks for yournhelp

No problem at all.... It sounds like you have gone as far as you can on a diy basis or with the equipment that is available.... Ford equipment will find the fault for sure.... Im very pleased to have helped you ... Please click the Accept button now - Thank you ...and if you do need to get back to me / wish to later - you can do ...just come back then to this post and re use the reply button - your reply will then come straight back to me.... Best Rgds and all the best with it -- MIKE....

Expert:  Mike replied 6 years ago.
Hello again...

Im sorry , the CHAT system seemed to stop responding - so I switched us to Q & A......

However - all the info I have given you is showing just need to scroll up...

I Sincerely hope I have helped you ...but do ask me if you need anything more...

Kind Rgds - MIKE...

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