• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Jeep died/won't start

Ecomike said:
Most repair places specialize in just certain tasks that call for parts swaps on obvious bad parts. Leaking coolant pump, radiator, dead alternator.

Today's electronic controlled systems with computers, sensors, digital control devices, are the highest tech stuff there is, that would challenge even a hands on design and field service chemical plant systems engineer like me, much less an every day shop mechanic. Most Auto shops hate electrical gremlin issues like yours, because they can eat up $1000 in shop time and only take a 50 cent wire cut and solder job to fix. Hard to charge enough to even break even without the customer raising hell.
Click to expand...

At least jeep 4.0s are comparitively simple. But still, I don't think I can take my grandparents 93 sable wagon much longer lol
 
rwat96 said:
I hope it doesn't end up being that much of a pain to fix, we will see. And thankyou!!
Click to expand...

The fix is usually easy, finding the damn thing is usually the Pain.

One complication is dozens of common grounds. One loose one (one ground location with several wires) and all the voltage from several devices start to wonder into other devices hunting for a path to ground and you hit the electric window switch and the radio turns on instead LOL.
 
Last edited:
Ecomike said:
The fix is usually easy, finding the damn thing is usually the Pain.

One complication is dozens of common grounds. One loose one (one ground location with several wires) and all the voltage from several devices start to wonder into other devices hunting for a path to ground and you hit the electric window switch and the radio turns on instead LOL.
Click to expand...

Ya that is what has agrivated me this whole time is not knowing what it is. And idk wouldn't it be convenient to be able to roll down the window and turn on the radio at the same time? That should have been a factory option!
 
Ecomike said:
That engine block dipstick ground even got me, not long ago, after 8 years of preaching about cleaning and refreshing Renix ground connections.
Click to expand...

Me too, and I'm the major preacher about the dipstick ground. My 90 MJ would have a slight "buck" while driving. I tried all sorts of thins. Finally resorted to hooking up the factory ester. Nothing found. Removed, cleaned , applied OxGard to the connectors at the dipstick tube stud and all is well... Keep in mind that area was refreshed 8 years ago without the use of OxGard.
"
 
cruiser54 said:
Me too, and I'm the major preacher about the dipstick ground. My 90 MJ would have a slight "buck" while driving. I tried all sorts of thins. Finally resorted to hooking up the factory ester. Nothing found. Removed, cleaned , applied OxGard to the connectors at the dipstick tube stud and all is well... Keep in mind that area was refreshed 8 years ago without the use of OxGard.
"
Click to expand...

I finally moved all the dip stick grounds (sensors) on my 87 2WD rig to the battery post clamp, except for the big ground needed for starter motor, for that very reason. Much easier to reach, clean and refresh at the battery clamp.

That was one of the worst places Jeep could have put the sensor grounds IMHO
 
Ecomike said:
I finally moved all the dip stick grounds (sensors) on my 87 2WD rig to the battery post clamp, except for the big ground needed for starter motor, for that very reason. Much easier to reach, clean and refresh at the battery clamp.

That was one of the worst places Jeep could have put the sensor grounds IMHO
Click to expand...

Oh that is why that ground is so important. I hadn't looked close enough to realize it was the sensor ground. That will definatly be the first thing I try.
 
rwat96 said:
Oh that is why that ground is so important. I hadn't looked close enough to realize it was the sensor ground. That will definatly be the first thing I try.
Click to expand...

Also when you do, you need to get both sides of every wire connector down to bright clean metal, and the block to bare un-oxidized metal as they call it. Then use that di-electric grease they sell for light bulb sockets on the surfaces before reassembly.
 
Ecomike said:
Also when you do, you need to get both side of every wire connector down to bright clean metal, and the block to bare un-oxidized metal as they call it. Then use that di-electric grease they sell for light bulb sockets on the surfaces before reassembly.
Click to expand...

Ok sounds good, thankyou!
 
Ok so a quick update.
So I cleaned the dipstick grounds and checked and cleaned the battery to block ground and block to firewall. When I drove it the wandering idle on decel/coasting still was there, I didn't drive it enough to see it it would start dying on me again at idle cuz I usually have to drive it for a few mins for that to happen, as I didn't have time to. I plan to test the map sensor tomorrow and if that isn't it do a general run through of the wiring harness.
 
Somebody help me out here, did the 96 have an EGR valve? Does his problem sound like a rare but possible EGR valve issue?
 
cruiser54 said:
90 was the last year of an EGR valve.
Click to expand...

Ya and a bad one would cause a vaccum leak as well and I figured out today that my jeep held a vaccum for about 2-3 days which surprised me. So even if it had it it wouldn't be it.
 
Ok so today I drove the jeep around with the intention of causing the stalling issue to start occurring again for the propose of troubleshooting, but after 45 mins nothing happened. And the erractic idle issue slowly dissappeared, as if the pcm was self adjusting after being reset, which I have done multiple times throughout this process. So maybe the weird idle when coasting in gear was maybe because the pcm was still re learning? And as far as the stalling issue, I am not sure if it is related or not so it could very well die on me again. But if it doesn't stall again at some point soon then that means the dipstick ground was indeed the problem. We will see with time I guess.
 
rwat96 said:
Ya and a bad one would cause a vaccum leak as well and I figured out today that my jeep held a vaccum for about 2-3 days which surprised me. So even if it had it it wouldn't be it.
Click to expand...

Yes and no, Yes in regards to the vacuum-diaphragm not leaking, but no in regards to the metal on metal seal area between the exhaust and the intake which can get crud-ed up and leak exhaust into the intake manifold and cause the engine to run too lean.
 
rwat96 said:
Ya and a bad one would cause a vaccum leak as well and I figured out today that my jeep held a vaccum for about 2-3 days which surprised me. So even if it had it it wouldn't be it.
Click to expand...

That is not possible in the intake manifold areas where the vacuum is created. You must have been testing an area blocked with a check valve?
 
Ecomike said:
That is not possible in the intake manifold areas where the vacuum is created. You must have been testing an area blocked with a check valve?
Click to expand...

It was at where the vaccum bottle is that is in the bumper, but I relocated it to the engine bay because of an aftermarket bumper. I guess that area is blocked by a check valve then?
 
rwat96 said:
It was at where the vaccum bottle is that is in the bumper, but I relocated it to the engine bay because of an aftermarket bumper. I guess that area is blocked by a check valve then?
Click to expand...

Has to be, yes.
 
I've had the same problem with my 98 Jeep. I have a new fuel pump and pickup strainer. I've also had the CPS replaced. Then he wrapped the full rail in heat wrap because of a published notice from Jeep regarding a vapor lock in the fuel rail around #3 injector. Also used a lab scope to graph the waveforms of the crankshaft and camshaft position sensors. All that and the ignition coil were ok. The 5 volt reference signal was ok also. Any other ideas?
 
You must log in or register to reply here.

Similar threads

WGxj
1997 XJ 4.0L AW4 Long Crank Problem
Replies
5
Views
72
Tim_MN
Tim_MN
F
Stumped on this one!
2
Replies
29
Views
4K
Bent
Bent
N
New Engine is Hard to Start
Replies
0
Views
33
NGThomas
N
C
Cranking Time
Replies
6
Views
79
CBJeeper
C
J
Cranks, Fires, Dies - 1991 Briarwood Restoration
Replies
17
Views
3K
Jam Master Jay
J
Back
Top