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Discussion Starter · #1 ·
Hello all,

First post -

Occasionally my Mondeo 2.0 petrol struggles to start, the battery is new last year (Bosch S4) and I put in new spark plugs in a few months ago.

My next suspicion is perhaps the ignition leads, does anyone know what the resistance should be if I measure it? (In 20 Kilo Ohms?)

Maybe it might be something else.....any suggestion much appreciated.

Cheers!
 

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out of curiosity, when turning the car off, as the engine starts to die, floor the throttle pedal, this will draw fresh air into the combustion chamber. If starting is better, have a look at the egr valve...

best off buying a set of decent leads if you have suspicions... The uprated ones like magnecor can be cheaper than ford ones, don't buy really cheap leads, or they will become your problem... lol
 

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Discussion Starter · #4 ·
out of curiosity, when turning the car off, as the engine starts to die, floor the throttle pedal, this will draw fresh air into the combustion chamber. If starting is better, have a look at the egr valve...

best off buying a set of decent leads if you have suspicions... The uprated ones like magnecor can be cheaper than ford ones, don't buy really cheap leads, or they will become your problem... lol
Will try that trick in a bit,

Nearly bought some leads from Euro....I'll have a look at the magnecor ones and order them today. Cheap part anyway.

EGR valves seem to cause more problems than they solve, might just blank it off!

Thanks for the advice.
 

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Discussion Starter · #5 ·
Whilst running take each lead off individually and use a test light or something getting closer and closer, this will quickly identify a weak spark

Although I doubt it's that, you'd more than likely have a misfire
When you say test light, do you mean a voltmeter? I was wondering if anyone knew the resistance in ohms that ignition leads should have. All I know is that the voltmeter should be set to 20 kilo ohms :p

Probably easier to just change the leads and see what happens.

Thanks for the tips!
 

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No
Something like this
http://www.toolaid.com/sites/default/files/23950%20Color%20Photo.JPG
Hook up to battery negative.
Take off ht lead and move closer together to see how strong the current is. Looking for it to jump a couple of inches.
You will easily see if a particular ht lead is weak. If all weak repeat at coil pack.
Cheaper to test them than start spending money to fix somethin that might not be the problem.
 

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Ok try it for awhile with using a full tank. See if it occurs only with less than half.
The fuel pumps on these cars are submerged and can play up.
Lots of things can cause your issue so this might help eliminate at least one thing off list.
Intermittent missing can be electrical or fuel related.
 

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This is where a decent diagnostic tool would come in handy. One that fives live data and an ideal figure to compare how components are performing compared to what the ecu is looking to achieve
 

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Foot half on throttle when starting. See if that helps.
Sorry about the thread-jacking, but I have exactly the same problem. This morning the car didn't start (again) and I tried to put my foot half way down on throttle as suggested. It started immediately. What does it tell you?

The thing is that the starting problem doesn't occur all the times. Just every now and then it won't start.

Thanks
 

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It'll be letting more air in past the butterfly valve in the throttle body.
If it's not just a coincidence then I'm leaning towards the idle control valve or even a throttle position sensor.
I'm not sure how the mondeo works, but typically when the tps indicates the pedal is not being pushed the idle control opens the butterfly valve slightly as not to strangle the engine.
 
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