1967Kaiser

I have a 1996 Cherokee XJ, with the 4.0 6 cylinder, auto transmission. 4x4. that has been randomly shutting off

This started about January, but has been happening more frequently lately, first two times it stalled/ died while idling, but now happens whenever, in gear, out of gear, on accelerator, on brake, turning either way.

Now I have searched pretty heavily the past few days, but my particular symptoms don't seem to match the usual suspects, because it does not appear to be heat related, when it dies(no stumble or anything, acts like you just turned the key to off) I can turn it right back on by slipping it into neutral(if it happens when driving)

I have checked everything I can, and everything appears fine, ran it in the driveway and tried to get it to shut off by wiggling every wire I could touch(twice to make sure I didn't miss one)(I did swap out the relay from fuel pump with a matching one, but did not appear to solve the issue.)

some recent things(although it was doing it before any of these as well)
New cap and rotor, Plugs, Wires, Fuel lines(leaking at quick connects) fuel filter, air cleaner, cleaned throttle body, IAC,TPS.

I do have a leak in the gas tank at the fuel sender, seems the sender is rusted out and I have a pinhole leak, so I have stopped filling it up more then 2/3 tank, but being a 1996, it seems no sender fits, I tried the junkyard, and even picked up a 95, and 97 sender, but neither fit.

but hopefully someone has an idea? I did think of CPS and Camshaft position Sensor, but those appear to be mainly heat related, although if nothing comes up I may have to try them.

Radi

I'd take a look at the ignition switch connector, see if it looks overheated. It's a common failure. Of course there are plenty of other exciting possibilities
Relays and fuses in the PDC- give them a shake too.
No CEL or codes?

'96 can be a bugger with certain parts. Best bet is to find another '96 in a scrapyard and rebuild it's fuel pump assembly with a new pump.

XJwonders

1996 fuel pump is a standalone year only 96 will fit

1967Kaiser

Tried the fuses and relays in the PDC, I even thought, maybe the power wire to PDC, so I cleaned that, no luck.

No CEL or stored codes, this has happened maybe 10 times now? at least once a month up till the past week or so where it seems to be every few days.

I'll check the ignition switch, but I don't loose any electrical power, just the motor "dies", I feel that if the ignition is faulty I should loose more then just the engine, like my radio for instance.


And I have the local junkyard keeping an eye out for a '96, almost had one, but was rear ended, and the whole gas tank was smashed into the axle and floor-which had happened to destroy the sender

50.Cal

Good call. Ill check for codes tomorrow!

Radi

They're actually separate circuits in the switch. The engine only gets power in "ON", the accessories get power in either "ON" or "ACC".

1967Kaiser

ignition switch looks fine, doesn't appear burnt. But I have another symptom to add(actually maybe two), started last Friday or Saturday, first two times were almost unnoticeable(1500rpmish), the last one(happened tonight on way home, 55mph/2000rpmish). First two times were a very small burble/hiccup, rpms dropped only about 1-200, tonight it was major, it actually caused the jeep the jerk around as it fell to almost nothing in rpms, not backfiring at all, (I slipped it into neutral quickly, but did not need to restart as it did not die, so I slid back into drive)

the second is a slight tick noise, goes with rpm, almost sounds like it is coming from the distributor- but I will need to pull my stetho out to verify. I can barely hear it at an idle, and the fan noise makes it unable to hear anything above probably 1000rpms or so

syncview

it sounds like the CPS is on its way out

1967Kaiser

So there is definietly some surging and missing every now and then, looks like it is mostly between 1,500 and 2,000RPM. the computer is still not storing codes.

I did replace the coil(at $10 it was cheap) but the symptoms persist.

my distributor is definitely the culprit for the ticking, looks like the shaft has a little play(side to side, not rotational...well it has rotational play, but every distributor I played with has rotational play) but it is not much, but is it possible it is enough for the rotor to be hitting the cap-or even hitting the pickup sensor?

F1Addict

Agree. CPS failure is not temperature dependent, they just slowly fail. When they do, victims tell the same story you have told.

madmanmarty

when it stops, you need to check for spark, then fuel pressure.

1967Kaiser

Ok, I know how to check for fuel pressure, but how would I check for no spark, if it is able to start right up?, it literally starts up faster then it does in the morning, the second its in neutral, I barely twist the key it fires right up.

I'm waiting on a fuel pressure gauge, should be her in a few days-couldn't find my other one...typical, I'll probably find it after this is all settled.

97grand4.0

The biggest improvement I saw, next to the fuel system, in drivability and idle stability was when I replaced the distributor. Yes that little wiggle is key. Mine idles like a new car now. Think about it...
One other note, beware anything but a MOPAR cam sensor, all the aftermarket dizzys are good new parts, but the aftermarket sensors are a no fly. Count on and plan on getting one with not just oem, but genuine mopar sensor or you will be fighting rough idle and no starts all over again. Not saying this is your problem, but it's sure one of them. And yes, if it's loose enough, they are sure known to clock the sensor . absolutely. You say you hear it clicking, means it is hitting it.

1967Kaiser

replaced the distributor, idle got a little off, almost like it is missing on a cylinder, but it comes down to an idle without the little "blip" it always had(just before it would hit 750, it would jump up to 1000 quickly, then drop to 750 and stay there), seems a little better on the hills as well(more power,seems like it wants to climb with less rpms then it used to).

but it has been acting up more often too, so I guess I just need to replace that sensor(crank) and see if that works. ignition switch still looks fine, and fuel pressure stays right at 48psi idling and running(in park, no load), 42 psi when I turn the key on.

still no response from anything when I wiggle all the wires in the PDC, or around the engine, so I think connections are fine

oh, odd thing the other day, occasionally the tach would drop to zero, and it definitely sounded like the engine was off, but it would catch and fire back up before I could even touch the key or slip it into neutral, so I'm guessing that the crank sensor was lost, but before the engine actually stopped rotating, it picked it back up and would start running again? is that plausible? if so probably definitely the crank sensor.

97grand4.0

That sounds more like a secondary ignition failure, check spark wire connections are on tight, etc. then I'd check fuel system. I had ckps and cps failures, neither one did that. just saying.