Compression Test Results Surprising?

[mcowing]

88GT, pretty much stock
I did the self test KOEO and KEOR and got a few results which I might post later. I was mainly interested in the cylinder check. It flashed 7, four times. I swapped plugs and wires and it still flashed 7. So I did a compression test and here are the results (used a digital gauge)

PSI
1 - 154
2 - 152
3 - 155
4 - 154
5 - 150
6 - 148
7 - 143.5
8 - 145

Are 7 and 8 too low?
The difference between highest and lowest is less than 8%.
Also, I tested in cylinder order 1-8 Is it possible the drain on the battery would cause a slower turn-over and less compression? I ask because the numbers got steadily lower from 1 to 8.

 

[General karthief]

Yes

 

[mcowing]

Yes

What might cause such a small drop in compression?

 

[General karthief]

Ring/cylinder wear, low cranking rpms, valve not sealing good.
Did you prop the tb open? An small screw driver with a plastic handle works without damaging the throadel blade. 8% is not a big deal on a driver.
How many miles on it?

 

[mcowing]

130,000 kms/ 80,000miles.
Yes had the throttle open. Like you said, 8% isn't a big deal. But why would it give me that code? Possible injector issue?

 

[General karthief]

Get a noid light and test your injector
Do the plugs look good?