Does does a drop in Kpa mean? For example the MAP sensor drops from 98 Kpa to 89 Kpa....?

 

Doesn't that mean that there is a restriction somewhere?
I'm actually not too sure, never seen it before.

 

I thought it represtented a restriction also.

 

My MAP kpa bounces all over the place between 25 & 100 - is this a problem?

 

MAP is used to measure engine load. 100% throttle=100 MAP. Btw, MAP and vaccum are inverses so at idle a low MAP means you have good vaccum.

 

My MAP is about 50 at idle. Is this good or bad or???

 

Given your setup that's about right for idle vacuum.

Remember pressure in the intake is limited by atmospheric pressure, which is elevation dependant. The best is 101.3 KPA at sea level. Be sure to compare MAP reading with engine off for reference.

At higher RPM's it's common for MAP to decrease (vacuum increasing) since there isn't enough time for the air to enter the cylinders. This will also show as a leveling of airflow, a decrease in torque - hence horsepower as rpm increases.

How to get more air in chamber? Hold the intake valves open for longer duration, a la bigger camshaft.

Hope this helps,
-Christian