IM takeing a stab in the dark here prob first thing that got looked at but have you checked the auto choke ? sounds like it to me it could be flooding the car causing the splutteing (reving helps because it sucks more O2 into the car giving correct air/fule ratio) then when it warms up choke comes unstuck and runs fine ?? had a verry simula problem with a old magna i had
anyway good luck post back let us know how you went on
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