Jeep: Jeep has no power, jeep wrangler, case check

Question
QUESTION: i have a couple of questions i have a 90 jeep wrangler with the 2.5 i know they don't have much power but it seems this one is lacking.First its hard to get started when cold even though its fuel injected it has a slight miss while idling and when driving it just don't have any power you can have foot barely on the gas or to the floor and it drives the same. It has new plugs and wires what else should i replace?  thanks for any help you can give me.
ANSWER: You should also replace the distributor cap and the rotor button. I would also check the compression.  I currently own the same motor and I am replacing the head due to a crack between the valves on cylinder 1.  Hope I could help you!

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QUESTION: Thanks i will replace the cap and rotor tomorrow. What should the compression be on theses motors? I also have a question about 4x4 it locks in to 4 low fine but i cant seem to get 4 high to lock in any idea what this could be? thanks for any help you can give me.

Answer
Your compression should be between 100 and 125 psi, really if all of them are with in 30% of each other the compression is fine.  The 4x4 problem you are having may have something to do with the linkage or the transfer case.  Check to see if the linkage is binding.  Hope I could help you!