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Mpi Running Rich & Hunting - Adjusting Mixture Etc?! Possible?!


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#1 electricfurnace

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Posted 30 July 2014 - 11:44 AM

Noticed our '97 Cooper MPI has been hunting a fair bit at idle.

 

I fancy it is running rich too, as the exhaust is quite sooty and it pops when backing off the throttle.

 

Question is, how to diagnose / tune?

 

I'm used to working on a Pug 205 GTI engine where running mixture and idle etc can be adjusted but have never done any work on our MPI- what adjustments can actually be made, if any?

 

On my Pug hunting can be caused by the mixture being too rich - so maybe thats why our MPI is hunting?

 

Or what should I check out/replace etc?

 

Cheers



#2 FlyingScot

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Posted 30 July 2014 - 03:02 PM

Not possible to adjust the mixture on these. Probably an air leak or one of the sensors is U/S fooling the ECU into over fuelling the engine. Check the exhaust manifold isn't leaking, engine temperature reading okay?
Best bet is to find someone local who has the diagnostic kit and get it plugged in and checked not just error codes but running values.
You will save a lot of time....
If you have a read in this thread you will find there can be lots of reasons and finding them without diagnostics can be tricky I'm afraid.

FS

#3 electricfurnace

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Posted 30 July 2014 - 03:05 PM

No leaks on exhaust, engine temp all ok. Was thinking maybe a sensor then?



#4 Ruckus

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Posted 30 July 2014 - 03:53 PM

Check all the vacum pipes, the one to the idle control valve and the pipe to the servo.

As said best is to get it diag'ed. Find a local MG place that has the proper Rover T4 system.

I had a problem that a few mini specialists all drew blanks on, a MG place sorted it in on session.

#5 tmsmini

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Posted 30 July 2014 - 05:08 PM

If the IAC has never been cleaned, it may be worthwhile cleaning it. However it would be best to have a diagnostic tool to perform a service reset after it has been cleaned. The ECU has attempted to adjust to is current condition and it will need to relearn. If it has never been removed soak the screws before attempting removal. The mounting point is plastic and you do not want to have it crack.

iacv-01.jpg



#6 electricfurnace

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Posted 30 July 2014 - 07:54 PM

Any ideas of any MG diagnositc places in South Wales or within 1 1/2 hrs drive that are known for being decent?

 

Where can I find the idle control valve?



#7 electricfurnace

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Posted 02 August 2014 - 11:41 AM

could you tell me where the idle control valve is?

Also - i noticed today the purge valve on the nearside in the engine bay was disconnected!! Plugged it back in but not had a chance to test. Would this cause idling issues?

#8 silver_toes

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Posted 02 August 2014 - 01:38 PM

MiniEngineBay.jpg

 

Idle air control valve is hidden under the pipes circled. Just has 2 screws holding it on



#9 electricfurnace

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Posted 02 August 2014 - 09:55 PM

Perfect mate - whipped it out earlier and it was covered in *******, cleaned it up and it's helped a bit






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