300CE - Starts and Dies off (Sometimes)

Hi guys,

I acquired a 89' 300CE (M103 engine) three weeks ago. Body is in perfect condition and just had the auto tranny overhauled.

Alright... 2 weeks ago, I tried to start her up but the engine would die off. It'd run if I depressed the accelerator but once I released, the engine would die off again. I tightened the cable under the air filter box (not the accelerator cable) and it was ok. I wondered if I was a conincidence.

Yesterday the same thing happened so I did the same thing and all was well again.

Q1. What does that cable do and where is it connected to? I was thinking maybe it's loosing tension and I need to get a new one.

Q2. Also, morning engine starts take a long crank and the engine seems to fire up "unwillingly". If this a sign of the fuel distributor leaking?

Thanks for all inputs.