How do I correct to make conditonal formula with number values ?

My main worksheet has at leat 24 columns and as many as 30 rows, all have
numbered values. Rows are defined names.

I want to get average values when at least 2 conditions have certain values.

I tried =SUM(IF(AND(MapKpa:MapKpa=40),(RPM:RPM=1000),grmcy c:grmcyc))
and answer given is really total of all 30,000 row values for grmcyc and not
when mapkpa values = 40 and RPM = 1000.

Also best would be if the conditions allow lets say when Mapkpa is between
40 and 45 and RPMs between 1000 and 1500 to have a window of grmcyc average

I used Sum but really want an average of grmcyc when Mapkpa and RPM meet the
conditions so I can build a results table of what the grmcyc average value
was from 20 to 105 KPA in 5 KPA windows along with smaller RPM ranges.

Thanks,