ECU mapping - ambient temp

[Dynion Araf Uchaf]

Hello,

I took the race car out for a track day yesterday ( Pug 106 16v). I had it mapped last year on the hottest day of the year, and yesterday it never got to be more than 5 deg C.

On full throttle the engine is fine, the colder air temp made it feel quicker than normal, however on part throttle (admitted this is round the paddock) it is an absolute nightmare, kangarooing around on anything other than full throttle. It's not always been like this, and during warmer months it's ok on part throttle.

Therefore can I assume its a weather thing, and the map works better when the ambient temp is more like 10-12 deg? Or could there be some other problem like a knackered IAT?

It was done by a reputable mapper - a lot of people in racing circles use him.

ECU is MBE 9A6 - mid 90's tech but more than enough for my Pug.

[stevieturbo]

Communicate with the ecu and find out what any temp sensor is reading, if one is fitted.

But there'd need to be some crazy setup going on for it to make that much difference. It could simply be a new fault.

Does it even have an ambient temp sensor ?

[Dynion Araf Uchaf]

It has an inlet temp sensor

[DVandrews]

Most ECUs have a table of fuelling adjustments against inlet air temperature which should compensate for denser or less dense air, perhaps this table has been setup incorrectly or the IAT sensor isn’t functioning as it should, connect to the ECU and have a look at the table and at the live reading from the IAT, check these are both OK.

Dave