Volvo: loss of power, psi cylinder, air leaks

Question
QUESTION: I own a 1988 Volvo 740 Turbo B230FT with 162000 Miles, when I depress gas pedal(speed 30-40 pmr)it's runs good but there is no increase in power and Engine choking when I drive on the hill!!
Temp gauge usually works right when I stop after I starting the Temp Gauge moves down&up also the Turbo gauge is near white line.
I had checked:
O2 sensor,Ok.
Throttle body,Injectors cleaned.
spark plugs, wires,Ok
Air mass,Ok
CBV,Ok
Fuel Filter replaced.
Fuel pressure,Ok
Knock sensor.
my guess is the Temp Sensor? any idea?

Thanks in Advance
ANSWER: Masoud,
Check the intercooler hoses for air leaks, test the exhaust system for blockage, make sure the timing advances as the RPM's go up.

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QUESTION: I have done your advise but I still have the same issue at the morning cold Engine the car is choking and cut-out power(no more then 35-40 speed)when I drive up the Hill the power extremely go down!so I need to use the Overdrive but at the noon day or warm weather the car runs smooth(65-70 speed)
I replaced the Coil.
my guess is ECU(sending wrong frequency to injectors),Catalytic Converter,

Thanks
ANSWER: Masoud,
You have tried replacing all the parts that noemally cause those problems. Take the car to a shop that works on Volvo and have them hook up there test equitment take some readings and see where that leads.
Could be the C/unit but I would wonder why only cold! If the converter was blocked up that would indeed cause loss of preformance. You could allways take the exhaust apart at the cat and drive the car see how it goes.

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QUESTION: Just you know,yesterday I opened all Fuel Injectors and one of the Injector Seal Cap was cracked!
ANSWER: Masoud,
I would replace that injector ans see how the car runs.

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QUESTION: I tested the Engine by compression tester kit so here is the result:
cylinder#1 110 psi
cylinder#2 140 psi
cylinder#3 140 psi
cylinder#4 140 psi

1-what is the problem the valves or gasket? and do you know how much costs to fix the issue? (by Mechanic shop)
2-Can I add some especial Oil so the Engine live longer?
3-how long the car runs like that?

Thanks

Answer
Masoud,
There is no magic additive to add to the oil to fix the low compression. Cost will be determined by the problem, it may have to be taken apart to see the fault. You might try a cylinder leakage test to see where the compression lose is from. No way to tell how long the engine will continue to run.