Engine Power How to Revive my Engine Power?

suggest fuel pump inside the fuel tank

Advice----- is to take it to a repair
shop, to have it properly diagnosed
& actually find something wrong

Check for vacuum line leak by removing the hose from the booster and plugging off. If the engine settles down and runs ok then there is a problem in the booster controls or diaphragm. Replace the booster if that is the case. Hard brakes is the result of no vacuum assist when you put the brakes on and the noise is air escaping into the manifold through the hole and making the engine run rough.

What kind of book is that?

You mean that the starter is turning (cranks) the engine but the engine won't start? Be sure it is getting fuel. Turn the key to the on position and you should hear the fuel pump in the fuel tank run for a few seconds. If so that is good. If the fuel is being delivered then possibly you have no spark which usually is the electronic ignition module. The only way to test it is to replace it. Your timing chain or belt could be broken or "jumped" as the third possibility. I am leaning toward ignition module being bad as they just die without warning and nothing can revive them.

If you have the 3.4L engine in your car you should check the anti-freeze level to see if it has gone down. Also, pull the oil fill cap off from the valve cover and look to see if there is a snotty-looking coating on it, or stick your finger inside the oil cap opening (engine off of course) and see if you feel a slimy residue. Pull the dipstick to see if the oil looks milky colored. Either of these things can point to a leaking intake manifold gasket and you have coolant in the lifters which is preventing them from pumping up once the engine is running. You may be able to revive them after fixing the leak and an oil change, but if this is truly the problem, I would just put in new lifters at the same time as it's no walk in the park to pull the intake again just to do something right the second time around. Hope this helps.

Usually a tune up consists of new spark plugs, plug wires, cap and rotor, fuel filter, air filter. But it still doesn't take care of the carbon build up in your engine, **** in your injectors, and sludge in your engine.

Here's what I reccomend: Purchase a bottle of seafoam. It's $13 and to clean out the c arbon in your engine you take off your break booster vaccum hose and **** up 1/3 of your seafoam. Then the other 1/3 of the bottle can be added to yuor gas tank to clean out the gas tank fuel lines and fuel injectors.
Lastly you can pour it in your crankcase but the oil will have to be changed 200km after.

There are a bunch of topics on the internet about this in way more detail. Please do look into it.

Also when you start up your car after putting the seafoam in your breakbooster line you will have to rev the engine so it breaks loose the carbon and when you rev it will smoke out of your exhaust and when you rev black carbon will pour out of your exhaust and you should get a smoother idle, accelation and will revive lost horse power.

Good luck and have fun

The plenum problem should not affect compression tests. It allows oil to get sucked into the intake and will cause carbon buildup, plug fouling, and pinging. If you have zero compression on a cylinder, it is usually a valve problem. Even a burned piston will make some compression, unless it has a big hole in the middle.
Sorry, but if your compression results are to be trusted (and it seems they are), then you have to tear a head off to find the problem, or at least get a borescope in it.

Check the power transistor unit (the small black box on the front of the engine, passenger side, slightly beneath the main black intake hose coming to the intake manifold). It has six or seven wires coming in one side and out the other. That part was the one warranty recall for the Z from 90-96. I'm not sure what year yours is since the question is listed as a generic 300ZX question, but the recall affected 1990 models and a few early 91s. The PTU was redesigned with a heat sink to keep it from overheating (the main reason determined to cause the failure). This is the unit that drives the signal to the coil packs to fire the plugs. If it dies, you'll have no spark and the car won't run unless it decides to revive itself or you change it. If that doesn't fix the problem, I'd look into the CAS (metal circular sensor, front of the engine, driver's side, one harness plugged into the side) - that is the cam angle sensor and can cause you to lose ignition as well.