'98 Mountaineer race/stall at startup
My '98 Mountaineer is having problems. When I start it, it will race then almost stall over and over. The colder the engine is, the worse it is. For instance, in my semi-heated garage, it's noticeable, but doesn't stall. In the parking lot at work (I live in the Northeast - it's cold.) and I have to work to keep it running. Once it warms up, it runs fine. So far, I've taken it to the shop 4 times. They replaced the O2 sensor the first time, cleaned the throttle bodies the second trip, replaced the mass air flow sensor on trip number 3, and a full fuel injection system cleaning on my fourth visit. All of this seems to have had no effect as the symptoms haven't changed. I saw another thread here about rough idling and replacing the upper and lower intake gaskets, but it didn't mention the motor racing in-between the poor idling.
Any ideas? I'm not much of a wrench, but I'm getting better each time something breaks.