Engine Cuts out after starting & idling rough

[volvov70pilot]

(presumably)...

After the starter engages the engine rev's to about 1200-1500rpms then begins to idle (presumably after the starter motor is disengaged). Several times that idling has resulted in the immediate shut off of the engine, the Engine Oil Pressure light comes on and the upshift gear light comes on.

Key in - ON - cuts out. Before I've done anything.

Also, when i'm decellerating it will sometimes cut out.

Works better in hot weather and doens't cut out as much.

Prior to this, there was an ECT error in the OBDII computer replaced the ECT (sens.) and the light still came on intermittantly but then this has since stopped coming on in hot weather. In cold weather (i.e. Jan - Feb) it was coming on, the ECT gauge would read 0 and there would be no hot air. The MPG was crap and after resetting the with Autozone's reader and clearing the fault it would re trip the code into the computer with the same error code. Remember this is all AFTER the ECT sensor had been replaced.

Any ideas? Are they related? It would seem to me that maybe the ECT is telling the computer that it's too cold, pumping gas into the engine and when the ram air isn't large enough to cope with the amount of excess fuel being sent to the fuel dividers the engine becomes flooded and hence cuts out...

Although with that in mind, when I accelerate the gas pedal just after starting the engine after it has initially cut off and i've restarted it, it will sometimes come down to idle just fine.

During the decelleration part of the drive, i.e. 40mph along a road and coming to a stop light, the engine will run down the gears to 1st (again, presumably) then once it gets there it will idle rough between 500-600rpms (instead of 900rpms), then the "upshift" light will flash and it will recover, or it will die from 500rpms to zero.

HELP!!

[Klausc]

You have at least 2 problems, if not more.
You replaced the ECT sensor, but did you replace the thermostat? After driving 2-3 miles, your temp gauge should be at normal, not at cold.

The tranny light should never come on, and if it does you need to find out why. So long as the light is on, you can read the codes for that also.
Have you tried shifting to N when you are stopped and the idle is too low? If the idle gets back to normal after N, then it may be your torque converter being engaged. That requires a dealer software fix.