TJ: Weird issues

[brokenujoint]

How can I start this?:

When my jeep starts up when cold it starts fine.

When I go drive it, park it, it will sometimes start and sometimes wont

It wont turn over, click, nothing. Dead in the water

I also notice that sometimes the fuel gauge will go inop and then the jeep will putter. If I dont tap on the throttle it will die. Sometimes it will restart but will often die out quickly after that.

It has good cranking amps and volts when it works.
I'll pop the hood, look around, smack on relays in the box, tug on cables, etc.
Sometimes it will start up again and sometimes it has to sit for a few.

Sometimes when it dies dead in the water, after a few minutes it'll just start up again like nothing happened.

I'm stumped!
Any ideas/ experiences?

[inVERt'D]

I know exactly what the problem is--an electrical gremlin! When the fuel gauge goes "inop" does the rest of the instrument cluster go dark? If that were so, then I'd suspect a problem in the ignition switch or wiring. If it's just the fuel gauge, it could be anywhere between the dash and the fuel tank sender. Obviously the fuel gauge wouldn't make your Jeep not run--but the wiring for it might be shorting out against something that would. When that happens and you get it to sputter back to life, are there any backfires or pops? That would suggest to me that your ignition was intermittently going out. The backfires happen because the exhaust loads up with unburned mixture, then POW. Had that happen due to a loose coil ground wire once. Otherwise you could be losing fuel pressure--fuel level sender wire shorting out on a fuel pump wire?

[brokenujoint]

Theres no popping due to loading up. This jeep is 16 yrs old. Gonna try to put all new fuses and relays in the relay box on the inner fender. Gonna get the battery looked at as well as the Alt. Thinking maybe its a starter solenoid perhaps. Gonna have to get a meter on everything when its happening and try to isolate the issue(s). As far as the fuel gauge I feel like the gauge just isnt getting enough juice because once I get it going again it reads normally. The funny thing is is that this is a "when hot" issue. It never happens when it's been sitting all night and its a fresh start up.Seems like a hot weather issue. It's intermittent as hell.
Happened to me the other day in a drive thru. Embarrassing has hell. My foot slipped off the clutch under a small load and it stalled out. Tried to restart it and WHAM. DEAD..Not even a click. No radio, nothing. Got out, popped hood, looked back and 4 people behind me were rolling their eyes like Oh hell no!!! I want my burger. lol.. I wiggled things around, got in, and it started up. But started weak. Had to rev it a little, then it was normal.
You know how when you disconnect your battery then hook it up and and start it up? The pcm has to re-config. Well, thats what it seems like its doing. It reads/adj and re manages everything then its fine again. It's like a complete electrical disconnect, then its back on.

As for the cluster, it only affects the fuel gauge. nothing else. the gauge drops, and the low fuel light is on. A couple of times on a cold start it started up normal and the gas gauge looked like it was dead empty then with in a few minutes it came up. Not sure if the gauge is related to the starting issue.

UPDATE: Now my freaking clutch is going out.. LOVELY!!!!

[inVERt'D]

Theres no popping due to loading up. This jeep is 16 yrs old. Gonna try to put all new fuses and relays in the relay box on the inner fender. Gonna get the battery looked at as well as the Alt. Thinking maybe its a starter solenoid perhaps. Gonna have to get a meter on everything when its happening and try to isolate the issue(s). As far as the fuel gauge I feel like the gauge just isnt getting enough juice because once I get it going again it reads normally. The funny thing is is that this is a "when hot" issue. It never happens when it's been sitting all night and its a fresh start up.Seems like a hot weather issue. It's intermittent as hell.
Happened to me the other day in a drive thru. Embarrassing has hell. My foot slipped off the clutch under a small load and it stalled out. Tried to restart it and WHAM. DEAD..Not even a click. No radio, nothing. Got out, popped hood, looked back and 4 people behind me were rolling their eyes like Oh hell no!!! I want my burger. lol.. I wiggled things around, got in, and it started up. But started weak. Had to rev it a little, then it was normal.
You know how when you disconnect your battery then hook it up and and start it up? The pcm has to re-config. Well, thats what it seems like its doing. It reads/adj and re manages everything then its fine again. It's like a complete electrical disconnect, then its back on.

As for the cluster, it only affects the fuel gauge. nothing else. the gauge drops, and the low fuel light is on. A couple of times on a cold start it started up normal and the gas gauge looked like it was dead empty then with in a few minutes it came up. Not sure if the gauge is related to the starting issue.

UPDATE: Now my freaking clutch is going out.. LOVELY!!!!

I don't see how your starter solenoid could be causing all of the symptoms above. I will say something, though. Electrical thingies operate within certain thresholds. Push those thresholds and problems multiply. For instance, if your battery is a little low, it can exacerbate a marginal ground or make your PCM malfunction. Your car may work/ break intermittently. Always suspect grounds, btw--very simple, yet often the source of problems that could otherwise be very time consuming and expensive to fix before you find out it was a ground all along. Heat is another factor that can destroy electronics or just make them function less efficiently. It can push a system that is working over the edge.

Anecdote 1
My Saab has electrical gremlins. One of them (answers to "Legion," whatever that means) seems to involve the main power circuit for the ignition, dash, and PCM. I know when it's acting up, because the dash/ cluster will go dark. One or two lights may be on, but dimly. The starter will function perfectly (it's happens to be a helluva starter), but the engine won't start. Usually if I wait long enough, the dash will light up and it will start as soon as I turn the key. It helps if my headlights are turned off. Sometimes the car has died going 60mph. Once it wouldn't start for a couple of hours until I jumpered a couple of fuses. My battery had been marginal for a long time and didn't last long after that hot summer day. I got a new one and these weird, intermittent problems, which had become increasingly common, disappeared until I let it get drained once or twice. Now I trickle charge it from time to time, which is a good idea anyway, I think.

Anecdote 2
Many years ago, my mom had otherwise dependable '79 Toyota that would start fine when cold, but wouldn't start when hot. Raise the hood and let things cool off, and eventually it would start up. Turned out to the igniter module, which was attached to the coil. Igniter get hot, no worky. Get new igniter, worky worky.

Anecdote 3
A have a good friend of who happens to be a stubborn old guy. One day the starter on his Toyota pickup suddenly stopped working. Don't remember if it clicked or not. Battery was fine, no sign of mouse eaten wires. Couldn't hotwire the starter. Soo, he gets it in his head that the starter must have died allofasudden. Now starters can do that, but my friend's starter is a gear reduction starter, which tend to be less sensitive to temperature extremes, and tend to die longer deaths. One of the things I first noticed when I looked under his hood was that the battery ground cable was attached to the front of the AC bracket where it bolts to the compressor. I said, [name redacted], that's bad juju. Let's put that ground somewhere else before we mess with the starter. But he was sure that ground was good, and wouldn't hear it. Of course, I'm the one who had to take the starter out, which was a total PITA. Bench tested "broken" starter--spun like a politician. I was hot, greasy, and wanted to choke a Toyota engineer, but my buddy was a lot closer, and he knew it. Put the starter back in, cursing Toyota all the while (why did they have to put that bolt BEHIND the starter??). Still no worky. I moved the ground to a bracket bolt that went into the engine block, and....worky worky. All that work and frustration for nothing--except my friend rightfully felt like a dumbass. After a few such episodes, my friend has become a little more reasonable, and I don't think I'll have to choke him.

The other moral of this story is that said ground had been working for a long time in that less than optimal location, when suddenly it didn't. Whatever miniscule amount of oxidation had occurred overnight had exceeded the threshold where that ground could function.

Got quite a few more, but even if I haven't exceeded your attention span, mine is reaching its functional threshold. :beer:

[aw12345]

Starter solenoid is easily checked, when it has a fit, make sure it's in neutral turn on the headlights, Jump the batterycable on the starter to the solenoid terminal if it starts your problem is somewhere else, if the lights go real dim or off you got battery and or battery cable issues. If the lights stay bright and nothing happens give the starter a few love taps with a hammer or a rock. then try again or keep the solenoid energized while you abuse the starter and it should come to life. That is about the easiest way I can think of to narrow down your problem. If the starter checks out start looking at relays for the starter, ASD and Fuelpump also supply voltage to the PDC or whatever the magic black box is called

[inVERt'D]

Art, Niles and I were just warming up to a rousing redneck discussion of stochastic limit theory and its application to electromechanical systems via theoretical statistical mechanics, and you interject with your "hit it with a rock" suggestion. I mean really, are you a redneck or a caveman?

Probably not a bad idea all the same....

[aw12345]

Beats being stuck and or having to walk, when you have a vehicle that's perfectly able to get you there after you tickle it a bit with a rock

[inVERt'D]

He stated in another thread that he hadn't even driven it in over 9 months, so we can deduce that it hasn't seen the rocks in quite some time. Your theory does seem to correlate with his Jeep's long convalescence and its sudden onset of problems. If the rock "tickle test" yields positive results, that would lend support to the notion that Jeeps need periodic (if not frequent) rock therapy. I can say from my own experience that the longer my Jeep sits in one place, the more pieces fall off of it. Exciting implications. If a tickle helps his Jeep, just imagine what a deep tissue massage on Sledgehammer could do for it!

[aw12345]

I guess that's why there is a trail called Sledgehammer, just run that and all is well, works for me

[6spdYJ]

Two things jump out at me here. The first being the intermittant start. If your starter brushes are worn or gummed up, they'll give good current - when they work. However, what's more interesting is the no radio bit. Start at your positive battery terminal and follow the fusible link. Try bending it with your fingers as sharp as you can, move about an inch farther and try it again. If you feel a spot where it gets crunchy or dead soft, you've got a bad fusible link. The adj signal kinda indicates that. A continuity check may and may not help. If you're at one of the lucky moments, it'll read good and throw you a curveball. If it checks good, obviously go to the ground cable and do the same. If that don't work - refer to Art's advice.

[inVERt'D]

Oh for the love of SCIENCE, hit it with a ROCK!

[brokenujoint]

You guys crack me up. As for the sitting around for nearly a yr. Yes it has ,but I take it out for a cruise now and then. This problem hit me once on John Bull about 4 yrs ago and I chalked it up to chip creep with the fuses under the hood. I reset some of them and the jeep started. Only recently has it gotten much MUCH worse. The weather is also MUCH hotter to. The jeep is 16 yrs old and I've abused the starter over and over again with a lot of 1st gear starts while on the trail. I think I just might get one to get one. As for the battery, I keep a trickle charger on it if it sits for awhile. Doesnt mean a cell or 2 might not be going bad. The battery is about 8 yrs old so I may get a new one as well for the heck of it. All of the battery cables from the battery to the starter,, the cable to ground, the cables to my fuse box, + and - cables are all a few yrs old and are made from 1 ought cable with HD terminals and military type fittings to the battery.
All I can think of in my mind is either the battery going south or the starter and its relays/solenoids. A good tune up to replace them regardless. Ignition system was tuned up about 7,000 miles ago. The jeep is well maintained and nothing is beat up under the hood.
Also, I have a prolock antitheft device that was a factory option when i bought it and it may be acting up. its a starter kill switch. I dont think that it should affect battery and dash pwr though.
On a side note (just remembered) EVERY TIME it wont start,it's from a hot start and it will give one click with the battery before it goes completely dead.. That's why I'm thinking stuck solenoid when hot.
Im off wed thurs and fri so I'll be tearing at it and figuring it out.Will get a new battery and starter just cuz.. Will also be starting my r/r of the driveshafts, trans case and all that crap for the clutch job. GOOD TIMES!

It would be a good idea if this forum had a write-up section. Even if its a reference cut and paste from online sources. When I find this problem's resolve I'll put details and hopefully it will help the next guy who has the same issues.

[6spdYJ]

8yr old battery, hmm... Keep the rock handy.

[HB Jeeper]

two things to check...corroded battery cables...pull them off and clean them good...//replace the battery as I saw it was "old". The last thing to look at is the ground cable from the battery to the block. this issue is definitely a ground problem. If you lose everything (radio, clock, dash lights etc) it has to do with grounding.

[brokenujoint]

battery terminals and cables were already checked. Why would a grounding issue only show up when it heats up?