TacoLibre

Hello everyone, first post here and having some issues diagnosing an issue. This car has been sitting for over a year and is a 290k miles auto example. It started with the old gas when I purchased it a few months back and I am now getting time to work with it. It had multiple issues but I will stick with those surrounding the engine since the issue at hand is that the car will not start easily or run below 1500rpm even though it will run quite smoothly above 2000rpm. I have replaced the airfilter, plugs wires, dist. Cap and rotor, fuel filter, water pump, and serpentine belt. The gas tank was almost completely empty and the car was ran some only on the old fuel before 5 gallons of non Ethanol premium were put into the car and also the fuel filter was changed out. Previous to all of the work the car started poorly but DID idle on its own. It should also be mentioned that in the process of doing all of this work there was a large vacuum/ oil breather line that goes to the valve cover and air cleaner that was broken. Due to part availability, this was remade using heater houses and fittings sadly additionally, the car is making white smoke out the exhaust and did only after I did the work to the car( hoping not a head gasket). I will do a compression check here soon. 1 last thing to take into effect is that when the water pump was replaced the replacement part did not have the correct diameter pulley to fit into the mate or inside of the fan pulley and also the hole diameter for the sensor that has 1 wire was totally incorrect so the hole was plugged with a plug that was actually included with the water pump. Please help as I am unfamiliar with the car especially the Bosch fuel injection system.