your code is very repetitive with some of those if statements

elements.gasoline = {
  color: "#5a271e",
  behavior: behaviors.LIQUID,
  state: "liquid",
  density: 1000,
  category: "testing"
}
elements.gasoline_engine = {
  color: "#6d5f5d",
  behavior: behaviors.WALL,
  state: "solid",
  density: 1000,
  category: "testing",
  conduct: 1,
  properties: {
    shocksToDo: 0
  },
  tick: function(pixel){
    if (pixel.shocksToDo <= 40){
    for (var i = 0; i < adjacentCoords.length; i++){
      var coord = adjacentCoords[i]
      var x = pixel.x + coord[0]
      var y = pixel.y + coord[1]
      if (!isEmpty(x, y, true)){
        var otherPixel = pixelMap[x][y]
        if (otherPixel.element == "gasoline"){
          deletePixel(x, y)
          if(!pixel.shocksToDo){pixel.shocksToDo = 0}
          pixel.shocksToDo += 10
        }
      }
    }}
    if (!pixel.charge && !pixel.chargeCD && pixel.shocksToDo){
      pixel.charge = 1
      pixel.shocksToDo --
    }
  }
}

elements.gasoline = {
  color: "#5a271e",
  behavior: behaviors.LIQUID,
  state: "liquid",
  density: 1000,
  category: "testing"
}
elements.gasoline_engine = {
  color: "#6d5f5d",
  behavior: behaviors.WALL,
  state: "solid",
  density: 1000,
  category: "testing",
  conduct: 1,
  properties: {
    shocksToDo: 0
  },
  tick: function(pixel){
    if (pixel.shocksToDo <= 40){
    for (var i = 0; i < adjacentCoords.length; i++){
      var coord = adjacentCoords[i]
      var x = pixel.x + coord[0]
      var y = pixel.y + coord[1]
      if (!isEmpty(x, y, true)){
        var otherPixel = pixelMap[x][y]
        if (otherPixel.element == "gasoline"){
          deletePixel(x, y)
          if(!pixel.shocksToDo){pixel.shocksToDo = 0}
          pixel.shocksToDo += 10
        }
      }
    }}
    if (!pixel.charge && !pixel.chargeCD && pixel.shocksToDo){
      pixel.charge = 1
      pixel.shocksToDo --
    }
  }
}

elements.gas_generator = {
    color: "#FFDD0D",
    category: "machines",
    conduct: 1,
    properties: {
    shocksToDo: 0
    },

    tick: function(pixel){
    if (pixel.shocksToDo <= 40){
    for (var i = 0; i < adjacentCoords.length; i++){
        var coord = adjacentCoords[i]
            var x = pixel.x + coord[0]
            var y = pixel.y + coord[1]
            if (!isEmpty(x, y, true)){
            var otherPixel = pixelMap[x][y]
            if (otherPixel.element == "gasoline"){
                deletePixel(x, y)
                if(!pixel.shocksToDo){pixel.shocksToDo = 0}
                 pixel.shocksToDo += 10
            }
            }
        }}
        if (!pixel.charge && !pixel.chargeCD && pixel.shocksToDo){
            pixel.charge = 1
            pixel.shocksToDo --
        }
        }

}

elements.gas_generator = {
    color: "#FFDD0D",
    category: "machines",
    conduct: 1,
    properties: {
    shocksToDo: 0
    },

    tick: function(pixel){
    if (pixel.shocksToDo <= 40){
    for (var i = 0; i < adjacentCoords.length; i++){
        var coord = adjacentCoords[i]
            var x = pixel.x + coord[0]
            var y = pixel.y + coord[1]
            if (!isEmpty(x, y, true)){
            var otherPixel = pixelMap[x][y]
            if (otherPixel.element == "gasoline"){
                deletePixel(x, y)
                if(!pixel.shocksToDo){pixel.shocksToDo = 0}
                 pixel.shocksToDo += 10
            }
            }
        }}
        if (!pixel.charge && !pixel.chargeCD && pixel.shocksToDo){
            pixel.charge = 1
            pixel.shocksToDo --
        }
        }

}