My 89 240 is having a devil of a time lately. I have to keep my foot on the gas to keep it running or else it shuts off. Now today it reached a new level of ineptness. When it shut off it would not restart until it rested for a while (like 30-45 minutes.) Prior to the last couple of weeks the car would idle, but very poorly, the engine was pulsating. Obviously I have a fuel problem but do not know where to start looking.