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Discussion Starter · #1 ·
Hello,
I am currently completely stuck on what to do! I have a mini one 1.4 (peugeot engine) with a misfire on cold but when it warms up it runs like a dream. This car has no codes stored within the ecu. The plugs have been replaced as well as a coil. it has also had new inlet manifold gaskets, timing chain and all the kit, and very recently a head gasket replaced. I can access live data on the scan tool and is brings up a misfire on a cylinder but every time its different!

Completely stuck. I would appreciate some help!!!

Cheers.
 

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13,595 Posts
Hello,
I am currently completely stuck on what to do! I have a mini one 1.4 (peugeot engine) with a misfire on cold but when it warms up it runs like a dream. This car has no codes stored within the ecu. The plugs have been replaced as well as a coil. it has also had new inlet manifold gaskets, timing chain and all the kit, and very recently a head gasket replaced. I can access live data on the scan tool and is brings up a misfire on a cylinder but every time its different!

Completely stuck. I would appreciate some help!!!

Cheers.
02 sensor
coolant sensor
would be worth pulling injector rail out with injectors on it crank engine see what fuel pattern you get,should have a atomised gas ball and all 4 the same,
crank position sensor maybe breaking down while cold when hot they expand and read correctly
what diagnostic tool are you using
on live data can you check vanos positions prescribed and actual see if its a timing problem/
i use autocom cdp on live data works well
below are screen shots of a 2008 mini 1.4 one with 55k after it had a new timing chain and 02 sensors
 

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· Registered
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4 Posts
Discussion Starter · #3 ·
02 sensor
coolant sensor
would be worth pulling injector rail out with injectors on it crank engine see what fuel pattern you get,should have a atomised gas ball and all 4 the same,
crank position sensor maybe breaking down while cold when hot they expand and read correctly
what diagnostic tool are you using
on live data can you check vanos positions prescribed and actual see if its a timing problem/
i use autocom cdp on live data works well
below are screen shots of a 2008 mini 1.4 one with 55k after it had a new timing chain and 02 sensors

I can get a live reading of the engine temp on launch diagnosis, so surely it cant be temp sensor issues?

also is those readings are the correct readings on what they should be?

Cheers for the help.
 

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I can get a live reading of the engine temp on launch diagnosis, so surely it cant be temp sensor issues?

also is those readings are the correct readings on what they should be?

Cheers for the help.
they are on a car that i had finished working on and done a last check diagnostic run on it just to prove my work, yep car was and has a run perfectly since.
i personally use either delphi diagnostics at work or i have autocom cdp or wurth snooper on my own projects not had much to do with launch diagnostics,
as for temp sensor working yes they can work put not correctly,
the process i would do tp check would be
1. cold engine first start of day, plug in diagnostic to read the temp sensor when cold the temp should match the outside temperature with in a few degrees if dont its faulty,,
2 start engine and watch the temp sensor on diagnostics it should start increasing within 3 minutes engine reving 2k,
3 keep engine running and revs 2-3k until fan cut in at point of fans cut in should have 100-109 degrees on the sensor and steady
i would also flip the injector rail out turn it over and crank engine and watch spray patterns see if one when cold is faulty sometimes they gum up and stick and heat clears it then cold gums back up again or a resistance issue in the windings maybe, if you could read each cylinder like in autocom you can it helps to find where the misfire is what cylinder or if one is worse than another, if all cylinders tends to point to timing chain or tensioner area or vanos sprocket maybe but with out a full diagnostics platform that covers such a deep way of doing it its impossible to pinpoint the issue other than throw money and parts at it,,, witch if i done that i would be looking for a new job fairly soon..
the temp sensor effects fuelling, so does the 02 sensors, there is also a knock sensor that monitor timing knock, etc, but you have no codes for any of these so i would lean towards a injector maybe or spark plug or even a compression issue that when heat builds up it expands and compression increases again and when cold drops again but that fairly rare all things worth keeping in mind and do the process for,
ie compression test hot cold then you know one part of what it needs to run right is there and you know its there,, same as fuel system you need to know the injectors spray evenly, same as diagnostics run you need to know the gear you use does have full live data function as with out i would struggle to find the problems,, with out using a scope on all components and try and work it out,
link below for what i use a lot autocom, the best bit of kit for money you can buy at present, so much better than what you have,
https://www.ebay.co.uk/itm/OBD2-for...933090?hash=item2155a71162:g:AqwAAOSwDXFciaxd
 

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Discussion Starter · #5 ·
Hello mate, took it out for a drive today and it does seem to be hunting for fuel when cold, however when it is at optimal temp it still has a flat spot. Went into live data and checked all the lambda readings and they all match up to yours, knock timing seems all good. Compression is very good with 260 on each cylinder. the only thing i havent checked is injectors but this seems to lead me more towards an issue with the throttle? what do you think?
Thanks for the help.
 
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