My wife's 95 945T (90k miles) starts fine on a cold (below 40F) start, but idles like crap for 20 to 30 seconds. If I hold my foot on the gas and keep it at 1500 rpm for 8 to 10 seconds, its fine. Car idles nicely when warm, and runs like a dream. When I pull the plugs, they look great. Gas mileage is about 23 in mixed driving.

I just replaced the ECT sensor and checked wires, no change. Just about everything that can be easily replaced has been in the last 6 months (all filters, plugs, wires, cap, rotor, etc.). Recently cleaned TB, checked for intake man leaks using starter fluid method, none found. Ran some top engine spray cleaner through last month, and two weeks ago ran a bottle of BG-44k through system. Cleaned IAC two weeks ago, idle drops when hose pinched. Swapping coils and knock sensors with other 940T makes no difference.

I don't think its the O2 sensor, as it is not supposed to be active until the car is warm, and gas mileage is good.

I know this is a small thing, but I am really stumped, not sure what to try next. I am beginning to think maybe the ECU is wigging out (not regestering cold input signals?), but I thought ECU's are an all-or-nothing deal. Anyone with any insight would be mucho appreciado.

Cheers!