Jeep fault codes

How long since tune-up? Any applicable trouble codes? Did you check primary voltage to ignition coil, engine cranking, dark green wire with orange tracer, use a test light and check for voltage. That voltage comes from asd relay. You may need to check cam and crank sensor, both. I realize you changed the crank sensor, already. Some makes and models, the computer has to see cam and crank signal, both, or it won't ground the asd relay.

Could be other issues?

sounds like a crank sensor to me it is located on the bell housing of the transmission on drivers side near the top

turn over or run
turning over is cranking but not starting/running
not turning over indicates seized motor , bad battery starter motor problems , bad ground
turning over is cranking but not starting ---broken timing belt/chain, crank/cam position sensors , no fuel , no spark , no injector operation
best run the fault codes as the fauty will be recorded there

run fault codes to check for cam/crank position sensor. check that the cam shaft is turning(broken timing belt/chain) check immobiliser operation.

I would start by going to an auto parts store and having them scan the computer for codes, even if the engine light is not on. i have heard about auto part stores saying they can not scan if light is not on. i am not sure if it is the scan tool they use or what but sometimes there could be a pending code where the computer is waiting to see the problem again before turning light on. if this is the case then ask them to scan it anyway or go to a shop and ask them to do it. the reason for this is that these trucks have crank sensor problems.

the next time is dies check for spark, remove a sparkplug wire and place a screw driver into the boot of the wire and place it near a ground, a metal surface and then have someone crank the engine and see if there is spark. if there is no spark or you got a code of the crank sensor then i would replace the crank sensor, but if you have good spark and truck will not start then try spraying starting fluid into throttle body and see if it starts and dies out if it does then fuel pump problem.

If you have a fuel pressure gauge then hook that up and crank engine and see if you have fuel pressure and how much.

I will say that this does sound like a bad crank sensor, it dies and then wont start for a while ...

Hello
The engine and automatic transmission in this vehicles drive train are fully electronically controlled by a computer called the PCM and TCM (Power Train Control Module, Transmission Control Module). When a problem like this or other drive-ability related problems occurs the computer stores a record of the problem (there are of course some exceptions to this, like the fuel pump, engine coolant temperature sensor and MAF sensor for instance) in the form of a fault code in its memory, to read these fault codes you must have the systems memory scanned with a special tool. Once the fault code(s) are read you then must perform the appropriate diagnostic testing to find and resolve the problem(s) DO NOT REPLACE ANY PARTS UNTIL A TRAINED TECHNICAIN HAS DIAGNOSED THE PROBLEM TO AVOID SPENDING YOUR HARD EARNED MONEY ON PARTS THAT MAY NOT CORRECT THE PROBLEM

try a new coil.some times a new coil will fail

check the ADS relay in the power center under the hood, swap out that relay for another on to see if it'll start-did you check to see if you have a signal at the crank sensor harness (should be about 5-7 volts)?

should have voltage on both posts of the coil. when the computer momentarly grounds the coil (in response to the crank position sensor sending it a square wave single). it will force a good coil to produce a spark. i would look at the coil again
good luck chris

i just had the same exact problems as zeeladys. It was the crank sensor shorting out and causing the short to shut down circuits in the pcm, volt gauge, fuel gauge, no spark. Locate the connector to the crank sensor, it runs beside the distributor, with the key to the on position unplug the connector and see if the gauges come back on. If so, simply replace the crank sensor and ur off and running