Quit, no restart.

I've searched and found a lot of folks with the "no crank, no start" symptoms my '87 4.0 is exhibiting, but I have an additional wrench to throw in.

I was waiting in line to get a smog test, just idling there. The idle suddenly dropped a little bit and stumbled, went back to normal, stumbled again, and then the motor died. Tried to restart it just to see what would happen, and got nothing - no click, no crank, and obviously no start. Had it towed 25 miles home (thanks, AAA Premier) where it continues to exhibit the same symptoms.

There's good power coming out of the battery at rest and the voltmeter had been reading normally in the 25 mile drive prior to the event. I get full power to the accessories when I turn the key as far as I can tell - the buzzers, fans, instruments and stuff all work as they should. There was plenty of fuel in the tank so I didn't run out of gas, but that would be moot anyway as the starter won't spin. I would suspect a bum starter, relay, neutral safety switch, etc. except that the XJ died mid-idle - this didn't just happen one day when I tried to start it.

Did I lose a sensor someplace, or is the ECU troubled, or am I making this more complicated than it is? Suggestions? TIA.

did you try jumping the solenoid on the starter to see if you could start it that way? it's odd that it would die while running like that. i would suspect the Crankshaft Position Sensor (CPS) but i dont know that it would go out and kill the engine while idling. at least if you can jump the starter and get it to crank over you know your starter isnt bad.

I haven't. I'll try that tomorrow and at least see if I can take the starter out of the equation, but that shouldn't kill it while idling either, right?

What if you turn on your headlights?
Lit well with and without key turned to start?
If they dim when trying to start, a bad battery, or most likely a major ground or hot connection very near the battery electrically.
If the lights stay bright at start something (positive) has likely just completly opened. You wouldn't expect that but anything is possible. Not too long ago in this forum I remember someone finding their main positive lead to the starter was practically open in one place, with your symptoms.

I did find that link:

http://www.naxja.org/forum/showthread.php?t=941424&page=3

I am one of thos guys with a no start forum post and ive replaced and checked the following with no luck yet so i hope you have better luck then me.

here is everything that has been done to date :
I checked the presure release valve at the front of the fuel rail and gas does spray out.
new airfilter
New plugs
New wires
New Cap and Rotor
Replaced the coil with one i know forsure is good.
New Crank sensor. pretty sure i can't screw that but if there is any other tricks for re-intallation please let me know. Is there anyway to screw it up...lol ?
Good compresion.
Motor turns over.
replaced map sensor
replaced all grounds
replaced ecu
replaced relays
replaced some connections
cleaned just about every connection there is
All of this equals NO SPARK THROUGH THE COIL. WTF is left ? someone please help me keep my sanity and tell me whats next.

Again good luck with yours, someone should get some.

If it's not cranking at all, you should start with the NSS. If it's an auto, trying cranking it in neutral.

Saudade said:

If it's not cranking at all, you should start with the NSS. If it's an auto, trying cranking it in neutral.

Click to expand...

That wouldn't explain why it died while running.
Assuming there is only one problem......

cygnus58 said:

That wouldn't explain why it died while running.
Assuming there is only one problem......

Click to expand...

My thoughts too. That did not stop me from trying to start it in neutral, waggling the gear selector around while trying to start, etc. No luck with any of that, but no surprise really.

A bad CPS would not keep it from cranking but would cause a no spark. The NSS is a typical culprit, easily tested.

Have you tried jumping it at the starter and/or starter relay to see if it cranks?

Check the ground strap from the rear of the valve cover to the firewall?

Well, I've not been able to start working on it til now. The starter turns over strong when I jump the posts (boy, it's heart-attack territory doing that with one's face a foot away from the starter...those things are a lot louder from up close!), so starter and solenoid should be fine. All the connections relating to the battery in any way appear to be clean and tight - again, a corroded connection someplace doesn't seem like it would result in the motor turning off all of a sudden, at least to me. But I'm no electrical expert.

Oh, and that firewall ground strap appears fine, also.

Does anyone think an ignition switch or lock could be the culprit here? Does the switch remain actively open while the car's running, and if it failed would it cause these problems? I have had one instance where I took the key out of the car but the ignition lock apparently wasn't set exactly in the OFF position, because the heater fan was still on til I jiggled it. Key out, fan on, not good.

What about a fusible link someplace? The only one I'm familiar with appears to come off the alternator, and since the system has been charging that one seems to be out of the equation.

Using a jumper, apply 12v to each of the green wires on the bottom of the starter relay (I used a small nail stuck in the back of each connector while still plugged in). If it cranks on both, then you need to check to see if one of them gets 12v when the key is turned to start. On mine, it's the one on the right, closest to the relay center. That one comes from the switch and energizes the relay. The 12v goes out the other one to the starter solenoid. If it doesn't crank on both, then your relay is likely bad.

If there's no voltage with key turned to START, then I'd suspect the switch.

Well it's official folks...I'm an idiot. I went to look where you said to, all ready with my jumper...and discovered that I have THREE of the green wires which you refer to: the two that were connected to the relay, and one that was just hanging there next to a bare post on the relay. I connected one to the other and poof! The Jeep started with the turn of the key. I say I'm an idiot because I'd been poking around that neck of the woods and somehow failed to notice before that there was a disconnected wire. Would have been nice if I'd seen that, say, before getting the thing towed home.

But thanks a lot for refocusing my attention on those green wires! Thanks to you, I'm not going to have to spend the time and money on this problem that I was worried about, I have a working second car, and I was just able to take a quick spin up one of the local trails that starts about an eighth of a mile from my house. Sweet!

It was weird...that wire was not exactly easy to get back on, so it's strange that it just fell off. But whatever...

Saudade said:

Using a jumper, apply 12v to each of the green wires on the bottom of the starter relay (I used a small nail stuck in the back of each connector while still plugged in). If it cranks on both, then you need to check to see if one of them gets 12v when the key is turned to start. On mine, it's the one on the right, closest to the relay center. That one comes from the switch and energizes the relay. The 12v goes out the other one to the starter solenoid. If it doesn't crank on both, then your relay is likely bad.

If there's no voltage with key turned to START, then I'd suspect the switch.

Click to expand...

All that matters is that it's OK now. If I got a nickel for everything I "overlooked", I be ...... Oh, never mind.

Nice thread am working on my no start problem now. that is an awesome pic. Had to leave my waggie at work today. I tried jumping the relay starter didnt budge. So I went to the junk yard and pulled a starter and a relay just for GP. And will put them in at work tomorrow to see if this fixes my problem.

christopher has your truck been stumbling anymore. Mine was doing it also. It died at a stop sign. started back up that time... went to get my lunch at godfathers. popped the hood check my tps and various other connections. closed the hood. got lunch. drove it back to work no prob. got off work and no start no crank but plenty of power. i dont see how these too are related but just want to know if you have stumbled and died any more.