Engine shut off like I turned the key off

Went out on local County roads. Had gone a good five miles, stopped to let the dog out. No trouble to restart, went about 300yrds, then down a small incline with wash out, and engine shut off like I turned the key off. I tried starting fluid w/ no results. Checked spark at plugs-none. replaced crank position sensor. still no spark. replaced cap rotor wires and platinum plugs as well. still no spark. I don't think it has a cam sensor. Hoping for any ideas?

 

lets start with wrong plugs, jeep uses a solid core plug. RC12ECC - keep in mind don't change after spending $$.

Ok no spark - 1999 XJ and I guess a 4.0L
Are the injectors pulsing whe trying to start
Did you check for codes? Yes even if cel is off.
Does the CEL come on for @2seconds every start attempt? Stays off or stays on?
Is there 12v at coil

 

Thanks Awrench. yes 4.0. I will try to check what you mentioned. But, what is the CEL?

 

CEL = Check Engine Light

 

So, yep. I was turning key on and trying to start and no cel light. But, if I wait like 10-15 secs or so, no bus lights up at odometer, kind of an old school digital sticklike readout, and check engine lights-up and stays on. I also hooked up my innova 5210 scanner ( I"m stil learning it) and it also only said "no bus" system, no other codes. Will my new platinum plugs be good with a Accel 42,000v coil? Also went with 8.2 thundervolt wires, summit cap n rotor. I know I'm kinda just throwing parts at it, but hoping for better than stock performance/but mostly reliability. planning to tackle install of a new BBk throttle body (62mm) after i/we get this thing running again.

 

Not a fast eash issue -

A no bus msg simply stated - the modules (computers) are not communicating. Yes there are several modules, often a sensor causes a communication failure. The sensors that operate on the K7 5v reference circuit is where to start.
I would check the wires at a sensor - the TPS is an easy place to start, probe solid orange wire at one end WHAT is voltage we want @5volts.
Next I would start unplugging 1 at a time then checking if msg is gone - CKP, TPS, MAP, oil pressure, and the CMP.

 

Not a fast easy simple issue - not a simple DIYer but here is some info-
A no bus simply stated the modules (computers) are not communicating on the network the BUS.
Often a sensor on the 5v reference circuit is shorted and shutting down system.

The sensors we will look at are CKP. TPS, MAP oil press and CMP.
Always look at the wiring just a few inches before connector- chaffed, rubbed thru, damaged?
I start at TPS (Throttle position) as it is easily accusable. Leave sensor plugged in for now.
With a multimeter probe the orange wire at one end- should see @5v - advise.
Next if no voltage - unplug the sensors 1 at a time as you worked on CKP (crank sensor) unplug first.
Did voltage at TPS change or the 'no bus' light go out?
Then unplug next sensor MAP (manifold pressure), did vltage change or msg go out
oil pressure sensor
CMP is the cam sensor.
Now unplug the TPS did msg go out?

Yes it is getting like rocket science

 

wow, ok, i knew i needed help. gimme a few days ill get get help w/ ur advise. thanks. im new to forum but id like to figure how to post picts. its beat up but not too rusty for WI.Thanks again this jeep deserves a good life.

 

local mechanic called today. A blown fuse. the fuse controls interior electronics? it caused the computer to turn off fuel pump. thats what i gathered over phone. I'll know more when I pick it up.