Will not start in cold weather but starts (and runs fine) if ECU is warmed. Is ECU bad or other fault.

 

Could be ECU, could be the connector.

Disconnect the negative battery cable from the battery, then 3 or 4 times, take the connector off and put it back on.

After that, reconnect the battery and see if it's improved some.

RwP

 

Ha, mine started doing the same thing. Before it was stalling when I pushed the clutch in/dropped it to neutral (at any engine temp). Now I replaced the IAC and now it has trouble starting cold and staying running, but runs great when warmed. Following this thread to see what solutions you may find.

edit: I did not try warming only the ECU and then cold starting the engine. I'll give it a try.

 

If possible I'd dismantle the ECU and check the soldered connections inside, check for charred, burnt or odd looking solder joints and get out the soldering iron and redo them.

I have another car where that's a common problem in the cluster.

Steve