Now that it is getting cooler the 97 e320 still has problems running till the engine gets warmed up then runs fine. One cold morning it would run and then act like someone shut the key off but before it stopped completely it would rev back up...we warmed up the crank position sensor with a hair dryer and it ran perfectly. I installed a new crank sensor and it still has the cold start/run problem. No codes. Temp sensor (Inlet air and coolant) are reading normally

dash code says something about battery charge but the alternator was tested and OK and we have a new battery (which we had tested an ok).

Any ideas on what to check???