ZJ Just Quits

Need more info... I assume it started again? Definitely check for codes. Why are you thinking no fuel? To follow a fuel problem, start by checking the fuel rail pressure and that it's within spec. Then, for fun check the fuses and relays for any abnormal visual signs. I haven't really heard of intermittent fuel issues with a fuel-injected Jeep, though.

Check the battery connections and grounds (including the block-firewall ground) to be sure they're clean and tight.\\\

Did you go through any deep water holes before the problems started? Maybe something got wet that shouldn't have... I always had problems with the TPS but that wouldn't cause a shut-down. Check your distributor for signs of water under the cap and loose wires.

One cause of random shutdowns is a dying crankshaft position sensor. Do you know when yours was last replaced?

does your jeep have a fuel pump shutoff sensor, it shuts off the fuel pump in an accident,if you do & it's malfunctioning jarring it could could shut off the fuel pump. or it can heat up ,melting the wire connector to it, stopping the power to the pump. wigiling the connector can get power back to the pump, had the latter problem with a ford I owned , drove me bonkers for months & cost quite a bit of cash to remidie.

Do you lose your guages too? There's a multipin connector under the jeep that can become loose and do the same thing but you'll lose your guages or the odometer will read NO BUS on it.

We had a 99 xj that did that. Engine died, gauges dropped. Turned out to be an intermittent shorting cell in the battery. New battery , problem. Solved.

If it starts back up, it can be a pcm. I had random stalls. Everyone i heard say throw this or that part. I ended up tapping pcm with wrench and it shut off. Found the problem. The true reason it goes bad is the screws holding cover on rub the board then short it out. If that is the case you are on borrowed time.

The CPS will make similar symptoms, no codes, complete shutdown, dead gauges. But, could still be anything. A quick loss of battery power will shut it down with no codes, too. Make sure that the battery terminal clamps are clean and tight, and the grounds... if they all look good, try unbolting the hold-down bracket and shake or raise/drop the battery a few inches while the engine is running and see if anything happens, that could point toward internal problems with the battery.

210* is fine, that's where the I6 is designed to run. If you want to lower the compartment temps, you'll need to move more air. I'm not familiar with the ZJ cooling system, do you have an electric fan plus the belt fan? If you do, you could rig up a switch to turn it on manually and keep air moving when you're going slow on the trails. Vents can help with cooling, but there are big performance differences depending on where they're placed. The 5.9L ZJ has vents at the front of the hood, which is perfect for cooling on the road as that is a low-pressure location and actually sucks extra air through the radiator than the fan can do alone. Most people put vents in the middle or closer to the windshield, these work great for low-speed cooling, but actually hinders cooling as it's a high-pressure location at speed and forces air down into the motor and will cause less air to move through the radiator. Just something to think about...

Sounds like the PCM. Dont throw parts at it. Test the parts. Look up the PCM screw mod, if that helps get yourself a new PCM.