I am really struggling with my 1986 Century 3.8 litre. I can't get the car to run. I can get it to fire some but it won't run very well. It will backfire and pop(barely runs when it does start). I have spark but it doesn't seem right. I pulled my crank position sensor off and I had a lot of gunk built up in the two slots of the sensor. Could this be a problem with the the fire and timing. I cleaned the sensor and havent put it back on the car. Is there any way to check this sensor before I put it back on the car.