Issue with PlotGoogle Map of R

Question

I am having an issue with the PlotGoogleMap package of R. When I am trying to plot my points(Lat, Long) using this package , then some of my points doesn't get plotted. I don't how to deal with this issue.

coordinates(engine) <- ~longt+latit # convert to SPDF
 proj4string(engine) <-  CRS("+proj=longlat +datum=WGS84 +ellps=WGS84 +towgs84=0,0,0")
 ic <- iconlabels(engine$vehicle_id, height=10,colPalette=rainbow(4), icon=TRUE)
 m <- plotGoogleMaps(engine,filename='myMap.htm', iconMarker=ic,colPalette=rainbow(4),mapTypeId='ROADMAP',layerName = 'Vehicle_id')

This is the code I am using ^

Here is a sample data.

Vehicle_id   longt   latit
    24143   86.4311 23.735
    24143   86.439  23.7392
    24143   86.4916 23.7275
    24143   86.5216 23.7695
    24143   86.5885 23.8091
    24143   86.6498 23.7984
    24143   86.7148 23.7937
    24143   86.439  23.7392
    24143   86.5249 23.723
    24143   86.5882 23.8088
    24143   86.7261 23.8197