Excel 2010 - X Y scatter plot will not plot empty cells as gap

Good afternoon everyone! Up to now I've been able to solve my issues my searching and lurking, but now I'm having some trouble that I can't seem to find a solution for by searching.

I'm plotting data that looks like:

6/22/13 1:00 PM
6/22/13 2:00 PM
6/22/13 3:00 PM 45.607
6/22/13 4:00 PM 45.89
6/22/13 5:00 PM 45.821
6/22/13 6:00 PM 45.436
6/22/13 7:00 PM 45.285
6/22/13 8:00 PM 45.445
6/22/13 9:00 PM 45.455


I'm plotting the time across the x-axis and the corresponding values on the y-axis. The first two time entries do not have any corresponding y-values, as the system was off and not recording values. I'd like the time entries with no corresponding y-value to plot as a gap in the data so that I don't have any zero values plotted but so that I can still maintain the appropriate hourly spacing on the x-axis. These seemed like it would be a simple exercise in right-clicking --> "Select Data" --> "Hidden and Empty Cells" --> Show Empty Cells as "Gaps", however I'm still getting zero values shown on the plot.

Can anyone explain why this is still happening? As I said, if I'm missing two hours worth of data, I don't want to the preceding and succeeding values to be plotted right next to each other, meaning I want to maintain the hourly spacing on the x-axis.

Hopefully I've been clear, but if you need any additional clarification, please let me know.

Thanks for your time!
Brad

I've finally figured out my problem!

The y-values were fuel quality measurements, and the gas analyzer would report whatever value it measured, even if the engine was off. When reporting these values, we only care to see values when the engine is running so I used a formula to check the engine operating hours to see if the engine was running or not. I then created another column that would use an IF statement to copy the fuel quality measurements only if the engine was running, and if the engine was off it would report "". This meant the empty cells were not actually empty, and so selecting the "Show Empty Cells as Gaps" option did not work.

TL;DR Make sure your "empty" cells are actually empty when trying to plot data with gaps!

Brad