Welcome to our Site for MG, Triumph and Austin-Healey Car Information.


MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGF Technical - Running too fat when cold?

I almost failed the MOT the other day, where the HC and CO were way way too high.

Driving an extra lap around the block yeilded a perfect result. Just before the test I had driven 30km on the highway so it was hot, it just cooled down slightly for maybe 10 minutes on the lift when they checked the suspension.

I guess it could be a worn cat after 9500km, but I have a suspicipn it is runing a bit too fat when cold. or instance it always seems like the car idles high when cold (around 1300-1500 rmp).

Any suggestions on checks?


(1.8i -97)
O Sander

This is temp sensor fault.

On the general board there is a kangerooing thread, do as stated in there
Will Munns

Oh, and BTW, although we say "lean" the opposite is "rich" rather than fat
Will Munns

I had the same thing, cleaned the connector of the temp sensor and all was well again.

Johan Slagter

So, in my case the problem to seem intermittent. I guess this could be bad contact, but also bad sensor.

I think i might try to measure the signal from it. What is it, a PTC-resistor, or?
O Sander

No, NTC, see
Will Munns

Will Munns

For those wanting to know what the above means, here's a little info.

It's actually a "NTC Thermistor"

NTC = Negative Temperature Coefficient.
(decrease in electrical resistance with increasing temperature)

Thermistor = THERMally sensitive resISTOR

HTH someone.



This thread was discussed between 10/05/2005 and 13/05/2005

MG MGF Technical index

This thread is from the archives. Join the live MG MGF Technical BBS now