Hello Guru's,

My car has been intermittently hesitating when trying to accelerate in colder weather (ie. -10 to -15C). This problem has occurred on two separate occassions already when the engine has been driven for ~30min. The car refuses to go above 40kph and the RPM's hovers at 2500 even though I have floored the gas pedal. When I come to a stop, the car will idle very roughly bouncing around 700 to 800 RPM (Normal idle RPM is @ a solid 900; which I know is a little high). I was wondering if any of you have a suggestion to solving this problem.

A possible related issue: I have also been having problems starting the car after it has sat outside over night in cold weather. Symptoms: Car Starts, idle surges to 2500 RPM then drops to 600rmp and surges up and down between 600-1000 RPM. Sometimes it stalls and this can only be avoided if by flooring the gas pedal until the idle hunting stops.

Thanks in advance.

Sincerely,
Tim

Note: I have cleaned out the IAC motor already, replaced the O2 sensor with a used unit, replaced the fuel filter and ran techtron & BG MI3000 through the fuel system.