This is my second winter with this car and I still have a cold start problem. It starts but it only seems to run on 3 cylinders for the first 30 seconds. If I make the mistake of letting it stall it won't start again like its flooded. There is a visible cloud of white smoke when this happens, as well as a gas smell. Both clear up after about 30 seconds and then the car runs normally (about 30 mpg). The tail pipe looks a bit black. The temp sensor has been checked, checked again, changed, checked, checked etc. I have swapped in multiple ECUs. The best runing one was a pink 561 from my 89, but extreme cold starting was a problem since the 561 used a cold start injector that did not exist on my 93.

The white smoke is what I am wondering about. I thought that indicates coolant burning, but its not loosing much if any coolant. The head gasket was replaced due to overheating by the previous owner. I am wondering if it is possible that coolant is leaking into one of the cylinders when the temperature gets down around freezing, and then the leak seals as the head warms up.