What could be wrong with my 2001 Jeep grand cherokee 4.0? It cranks and cranks but won't start. Gauges don't move and key light on dash has line through it. Changed CPS and cleaned battery terminals a

you used voltmeter at the pump?> or just didnt here it run
do say this...please. details, matter....
it told you low fuel is it? is the fuel gauge near "E"
why not state that first.?
dead gauges, be 1st right, smacks of gross power loss.
right>? not clear to me what no gauges means.
but the voltmeter is #1 no?

did you tests fuse that look ok. fuse that look ok can be bad.
no gauges, means all dead, no movement,
well the fuel gauge must work , does it, does it match reality?
cranks but never runs. good input there.

does not run for the jeep 3 seconds.? (ASD rules)
no 12vdc power to pump, when cranking,?
01 grand WJ jeep usa.
is the skim lamp off, the cluster lamp for SKIM security is first.
it must go out after key turn on, or it will never run, ever.
I can help.
WJ jeep
this jeep has a voltage gauge, it must read 12v keyon
if not power is lost, or battery low.
if cranks that tells me the fues blew.
skim cuts spark and fuel, not cranking btw.
2002 cluster
http://jeepdied.com/cluster2002GC.JPG
see that lamp 12, if stuck on car will never start but will crank.
the lamp falses if skim is not working or stays on for ******* key.
we SCAN ALL CARS NOW.
IF You can not scan a modern jeep then it can near impossible to diagnose (a hard cold fact)
IF the ASD fails to work, the PCM tells you every time
all 8 ways for it to fail.
but that takes a scan tool (any modern scanner works,)

http://jeepdied.com/no-start.html

A flashing key symbol normally means an invalid key. Do you have an other key to try? That all the gauges stay at 0 seems to point to a PCI data bus problem. Was the jeep parked outside or at least standing in the rain? Many times water ingress in connector C200 up in the passengers footwell area is the problem. The connector must be removed, cleaned/dried and reconnected. Ofcourse the source of the water ingress must be found, which many times comes from the windshield.

I cant explain the windows but the stalling can be the wiring harness at the under the hood . you did not mention engine size but i know on in line 6 the harness goes around the rear of valve cover if you move it around it will stall if bad.

did you replace the ECu with a used one or new. if it a used one did you match it to the old.why di you change the ECU.? when you turn the key in the start position does the fuel pump turn on? does it crank? do you know if there is spark if you pull one spark plug wire?

when you state it wouldn't crank, do you mean the starter won't engage or that it just spins over and doesn't start? if no gauges or no starter engagement, then check the battery, battery connections,and the starter for excessive amperage draw. if the starter spins and the engine won't start, then check crankshaft position sensor first. the crank sensor is a more common failure than the distributor or any of the other things you mentioned.

typical jeep gremlins on a 17 year old car
mechanics either replace all the computers and modules
or throw lots of unnecessary parts into it with minimal results

needs a volt meter an LED test lamp and a lot of time
tracing the wiring faults
starting at the battery through to the ECU and ignition

More than likely needs a crank sensor, Try cranking with the crank sensor disconnected, you should not get the dashes in the cluster. The crank sensors take out the communication system of the vehicle

check your starter...some have the ignition running threw starter solinoid

i know your battery is dead but if you have a charger put it on then turn the key to the on position for at least 10 minutes until security light stops flashing then turn key off and try to start.