Will not start

SOURCE: hey

the temperature sensor is it connect its close to the thermostat check that out cheers pierre

SOURCE: cranks but no start

check the fuses inside on the right hand front kick panel

SOURCE: 1990 jeep cherokee sport 4.0l

CHECK FOR BAD RELAY

SOURCE: long crank time but always starts

It may have good fuel pressure while running or cranking over, but sounds like it is not holding the pressure in the system.
Could be a weak fuel pump, and or fuel pressure regulator.

SOURCE: 2001 jeep cherokee sport 6 cyl 4 wdr cranks want start

If the data link is not talking to the computer check your ground at the computer and at the data link connector to see if the computer is even alive ground pin 3 on DLC with the key off then turn key to the run position if it flashes the check engine codes record them, if no engine light, does the engine light come on when you turn the key on then go off? if not, check fuses if not check power for pin on computer, if it has power you have a bad computer. But TEST THE GROUNDS IT IS THE BIGGEST FAILURE For these rigs or any manufacture. check that you have power also at the DLC too. if not you need a digital ohm meter and a subscription to http:///.www.alldatadiy.com and start reading the campaigns on that vechile for computer and trouble tree for dead DLC and computer. I don't have that subscription or I could tell you more where to look, if you need anymore help let me know. Also if the crank sensor could cause it not to run the fuel pump but so can the cam sensor. You need to find out if the computer gets it's pulse for the pump at the computer if it does then you need to test them both. There are three wires a ground a colored power wire and a wire to go to the computer you can test these sensors with a meter to see if there is a pulse to each. sometimes the fuel pump gets it's signal from the coil pack so it's important to have the subscription, you can do a search for each item and test them as needed and has a wiring diagram.