Limp mode when temperature drops... unsure, please help!
 

I was hoping someone could shed some light on a reoccuring problem thats been happening to my 93 FD3S.

The problem seems to only occur when the outside temperature is slightly lower than 20 degrees Celcius. I have not had the problem occur when the outside temperature is above 20 degrees. What seems to happen is the car puts itself in limp-mode, but an extremely severe limp mode. The car all of a sudden begins to flood and backfire, even normal driving is impossible as anything over 1/8 throttle the car backfires and stutters, all while bogging out.

Thats the best way I know to describe the problem. Otherwise, during start up and optimal weather conditions, it runs perfectly. Its only when the temperature drops slightly below 20 that the problem begins to happen.

A little bit about the cars modifications:

Race ported rebuilt motor
Non-sequential conversion
Apexi Intakes
HKS Twin Power
3" Stainless steel turboback exhaust
All emissions have been removed
The ECU has been modifed through the use of EPROM tuning (Tune was dynochecked and seems to run very conservative (rich) but good nonetheless)

I have tried adjusting the TPS, it is within voltage spec but I don't think the problem is related in any way. Hopefully someone can shed some light on the problem.

Cheers,

Matt B

Try checking/testing the sensors which react to temperature (and the ECU uses for management):

1. Coolant thermosensor
2. Fuel thermosensor
3. Air intake thermosensor

Also check your Knock Sensor. If the goo has leaked out of it, it could be overly sensitive when the car is cold.