Trooper cranks but wont start

IT IS LOOKS LIKE A FUEL PRESSURE LEAKING INSIDE THE ENGINE OR DEFECTIVE FUEL INJECTOR LEAKING . TRY DISCONNECTING THE FUEL PUMP RELAY. AND CRANK THE ENGINE IF ALWAYS CRANK WITH OUT OF FUEL (CRANK WITHOUT START) YOU HAVE FUEL LEAK INSIDE THE ENGINE
REMOVE THE INJECTORS RAIL UP EVERYTHING CONNECTED,PUT BACK THE FUEL PUMP RELAY TURN THE SWITCH ON AND FIND WICH ONE IS LEAKING. (GASOLINE IS FLAMMABLE TAKE CARE)

If your Trooper "cranks" but doesn't start or runs for a few seconds and stalls out, your fuel pump has gone bad. They are notorious for this. If you replace your fuel pump, replace your fuel filter. More information is needed though.

I would first pour some gas in intake if it fires or runs a little could be fuel filter or fuel pump.if it don't fire pull a plug out and crank see if theres spark that's where id start

Make sure battery has a full charge. If it cranks good but won't start, check the basics. Have a helper crank it while you visually check for spark at the spark plugs, if spark everywhere, use a gage and check proper fuel pressure. I looked at info for the 3.8L engine, 35--40 psi. Also, after you build fuel pressure, turn off the key, see if fuel pressure holds for a bit? If the pressure drops like a rock, check for fuel pressure leak. Check the vac line for fuel pressure regulator, if it has gas in it, the regulator is faulty, or a leaking fuel injector. The pressure could also drain back through fuel pump.
Also, check fuel injector pulse, engine cranking. Any applicable trouble codes?
Smell of the crankcase oil dipstick, if it smells like gas, either you don't change oil and filter very often or the engine is running very rich for some reason.

Does the engine crank ? If so do you smell gas ? If you smell gas you have a spark problem. If you do not have any fuel coming up then check the fuel filter and fuel pump. Let me know.

First, blow the fuel pipe with a strong air jet & change the filter. If this didn't work, change the main fuel pump (do NOT repair).

Disconnect the fuel line at the fuel filter. Turn the car on for the pump to be on. If you are getting gas pumped out, then your pump is good. If not there's most likely your problem. Then try the line at the engine. Disconnect and see if the gas is making it that far. Your should also be able to hear the pump come on if you open the gas cap and listen while someone turns the key to the on position.

fuel pump bad

NEED SOME MORE INFO... FIRST WHEN YOU TURN KEY TO THE RUN POSITION DOES THE CHECK ENGINE LIGHT LIGHT ON THE INSTRUMENT CLUSTER.. IF SO YOU KNOW YOUR COMPUTER IS POWERING UP... SECOND NEED TO KNOW WHAT IS MISSING...1...SPARK....FUEL OR INJECTION.. PULL ONE PLUG WIRE OFF COIL PACK HAVE SOME ONE CRANK CAR DO YOU SEE SPARK JUMPING ON COIL... SECOND SINCE YOU VERIFIED FUEL SYSTEM.. NEXT IS TO PLUG ONE PLUG AND SEE IF IT IS WET WITH GAS OR DRY LET ME KNOW AND I WILL HELP FURTHER

Start by making sure you have spark to the spark plugs. If not you may have a problem with the plug wires or coil. It's also possible you're not getting gas to the engine possibly from a faulty fuel pump.
If you change the fuel pump be sure to replace the fuel filter also.