I just checked compression last.night on my 96 4.0 my results were
148
130
118
149
150
147
1-6 took 3 cranks to get those readings last 3 jump right up to pressure. Did the same check with oil and nothing.changed for those cylinders. I check it because I've been having a real rough idle that i just can't shake.

 

Difference between highest and lowest is more than 40 PSI. Could be a ring or valve seal problem.

Unexplained coolant loss, OTOH, is one of the first indicators of a possible bad head/gasket.

 

Two low readings side by side, that don't come up wet...Yes. 130 is isn't that low though. My 02, yea, something is up, I wouldn't rule out a valve though. Exhaust valves have a tough job.

I just put compressed air to the plug hole on my Onan generator and could hear a hiss out the exhaust. (next thing you know I'm gonna have a hose in my 02 sensor bung, held to my ear!)

You cleaned your IAC on the TB? (and the TB?) How many miles?