'91 240 auto, stock.

Over Winter my 240 started first time, every time without problem. However, when the temperate was below -17C, I'd start it and just as the idle came to rest at the regular rpm it would die. The only way to get pass this was to hold my foot on the throttle for 5 seconds and then it would idle as it should.

The car started and ran great (still does) right up until two weeks ago.

When creeping to a stop the idle hesitates a little. It was merely a vibration I could feel through the brake pedal. Over the course of the last few weeks it's got progressively worst;

I can now feel the vibration through the car.

The hesitation idle 'kicks in' while cruising (no pedals depressed) below 20kmph (for instance, in a parking lot).

Then it's started hesitating when cruising (no pedals depressed) below 40kmph (for instance, in traffic).

When the rpms drop the whole car vibrates quite dramatically like it wants to stall. It feels like it's going to, but doesn't and never has. Surely it's only a matter of time.

It's been stormy here the last few weeks so this weekend will be my first chance to source the problem. My first port of call is to clean out the throttle body. Any other suggestions while I'm in there is greatly appreciated.

Thanks