In general, running below 1/4 tank is rough on your pump and filter, into the red id imagine is worse if that's the case week after week...

ok well, after reading all your advice, i decided to try something cheaper, switched relays with my a/c clutch relay, (identical) and found no difference. the thing about removing spark plugs/starter fluid to cylinders/reinstalling spark plugs, firing right up, was bothering me, so i changed plugs. (new champion copper plus, tehy didnt have ngk ) after new plugs were installed, it seems to run fine, started it, let it run for 10 mins, drove around the block, turned it off, waited 5 mins, started right back up, did an errand in a different vehicle, 20 mins later, started right back up. so. i am taking it to work tonight, and we will see if it starts right up in about 8 or 9 hrs.... i will keep you guys posted, if i get ANY funny business, then i am going to get a fuel pressure tester thingy.

Good.

Check your fuel pressure anyway, to establish a baseline. Read my signature....

Why would you want NoGoodKind plugs anyway? Chrysler = Champion

We use the 1/2 tank rule....

No less than 1/2 tank when a vehicle is brought home.

If I check and find one with less than 1/2 tank, that person loses their driving privileges for one day.

We have three kids, and five vehicles.

I know what can happen when a vehicle is constantly run with low fuel levels.

Chrysler actually found that the Champions did not hold up well under certain conditions. Not sure if this is due to manufacturing changes or what. NGK ZFR5N supercedes RC12ECC in some model years.

Not to hijack but....

I read through this thread and something is bugging the crap outa me. I'm 56 and have been driving since I was 16 and I have never heard this "keep it above 1/2 tank" thing.
How in the world would, say, keeping your tank 1/4 to 1/2 full cause damage to your fuel pump? And how in the heck would it damage a filter?
I can see that the full tank might put a little more pressure in the fuel pump's favor....maybe. Maybe there's something I'm missing here.

A full tank of gas surrounds the pump in fuel thereby keeping it cool, when the pump is warm it won't last as long. It won't "damage" the filter, it's just with a greater volume of fuel the crap in the tank is less "concentrated" to plug the filter.

This is what I was going to say. It makes the fuel pump work harder and therefore, fails quicker.

I'm glad you seem to have found your issue though.

so, the jeep ran great, i am kind of worried, it seemed like it was too easy, and there is a problem lurking waiting to devour a good day.... i'mma check the fuel pressure.... just one question, whats the rail?

Black bar in this photo:



The pressure test port is a small black twist-off cap sitting on the drivers side of the rail close to injector #2

Sometimes it is that easy. Bad plugs can raise all sorts of issues. What did the plugs you removed look like?

Running them dry burns them up. Running below a half or quarter tank repeatedly won't.

I've switched over to NGK ZFR5N plugs simply because the Champion RC12ECC plugs are getting harder to find at the parts stores. I see no big difference in performance with the NGK plugs in my motor.

Like Turbo_xj said, it damages the filter because the sediment in the tank(its there...just a fact of life) in a 1/4 tank or below allows more sediment to get pulled with the gas and simply clogs the filter faster, alongside that, the pump has to work harder as the fuel level drops to supply enough pressure to the rail, and just burns it up over time

Not to say that as soon as it its 1/4 tank your killing it, just that if that's a repeated cycle and your running 1/4 or less several weeks in a row or some such, it will deteriorate the pumps performance until you get issues