My 1995 Jeep grand Cherokee wont start.

The size of the bolts that go on the starter of a 1995 Jeep Grand Cherokee Laredo will depend on the model of starter you are using. In general, most starters use bolts that are M6, M8, or M10 in size.
To determine the size of the bolts you need, you will need to refer to the manufacturer's specifications for your particular starter. You can usually find this information in the documentation that came with the starter, or by contacting the manufacturer.
It is also important to note that the starter bolts may not be the same size as the original bolts that came with the vehicle. If you are replacing the starter, make sure to use the correct size bolts as specified by the manufacturer of the starter. Using the wrong size bolts could result in damage to the starter or the vehicle.

check node on injectors if none the computer is most likly your problem

Reset the timing and check starter ot see if working. Verify fuel pump is actually pumping fuel.

sounds like the ignition switch is bad

You might not believe this, but check your battery. Some of these vehicles have cut-outs when the battery level goes below a preset amount.
I work on Ford brands and on them, a low battery level will even disconnect the Alternator circuit and mess with the starter. Some even act up when the battery slightly dips below 12 volts.

Your antitheft can make your starter cut out. And If you think about it, all of the measurements to make the engine run are based on feedback of voltage and amperage. This is how the engine management system adjusts. If your prime source of power is low, then all of the following electrical readings will be low. Some may be too low to work.

Your fuelpump will hold pressure in a closed system for hours. The fuel pressure regulator will command the fuelpump to stop working if the fuel pressure is at maximum. Without responses from the other components and after satisfactory pressure, the fuelpump will turn off.

Your starter is bad.

I suspect the crankshaft position sensor, giving the info you provided.

Most likely the starter ,if they have worn contacts in the starter they will do this,and start good too,but you still have to replace the starter.

Check for fuseable link in main power cable.

the alarm seems to be activated. press the button and turn the key.