Grand Cherokee Help!!!

[5.0explorer]

Workin on a 94 Grand Cherokee Laredo with the 4.0 L6 for a buddy. Here's the problem: he went to the store and it was runnin fine, shut it off, went in, came back out and it wouldn't start. Here's what I know so far: engine turns over but will not start. Have fuel pressure at the rail but no spark at the dist. cap, because theres no power to the ign. coil. Looking at the wiring diagram noticed that the coil gets power from the automatic shut down relay, so I replaced that relay with a known working relay, still nothin. After some research telling me that when the camshaft position sensor (also called the distributor stator or pick up coil stator?) goes bad the engine will run with the last signal from the sensor until the engine is shut off, then it will not re-start. Sounded promising so i tested the sensor with an ohm meter as per the instructions and it tested bad, replaced it and still nothin........ and that's where I'm at. Any ideas or info. would be greatly appreciated. Thanks!

 

[rockreligious]

Maybe the crank position sensor. That went out on mine and it would crank but would not start. My .02

x2, crank position sensor failer is common on 4.0's, unplug harness, couple bolts and depending on year, is either one position or positioned by thickness of include paperbacking, 15 minute fix.

 

[Cody]

my old 4.0 ZJ had a bad cps, and it would kill coils. I went through 4 coils before I figured out that the CPS that was testing within normal range was still causing the problem. replaced it, no start, put a new coil (3rd in 2 days) and it ran fine and never had a problem again.

 

[lewis]

Where is the automatic shut down relay on a 98? I have similar problems but different issues

 

[4554x4]

Security system?

It could also be a security issue. Is the lights flashing? Cycle the key in the drivers door from lock to unlock a couple of times. This would reset the security system.

 

[5.0explorer]

It could also be a security issue. Is the lights flashing? Cycle the key in the drivers door from lock to unlock a couple of times. This would reset the security system.

Nope no flashing lights and i'm pretty sure it doesn't have a security system cause theres no fuse installed for it. But hey its worth a try.

 

[5.0explorer]

well you guys have pretty much all confirmed my next suspicion, so we'll replace the crank sensor and go from there, thanks!

 

[5.0explorer]

Where is the automatic shut down relay on a 98? I have similar problems but different issues

On this one the auto shut down relay is in the fuse box under the hood, if i remember right its the 3rd one in from the right. I just found it in the owners manual diagram and im pretty sure theres a diagram under the cover for the fuse box too.

 

[GEEPAHOLIC]

how are the fuel injectors ? in my 91 xj my injectors were dirty and i would crank all day long but not fire . i read through my repair manual and i found out that if you hold the gas to the floor and then kick it over it shuts off the injectors long enough to start and then i ran some "lucas fuel system cleaner " through and its been fine since . good luck

 

[5.0explorer]

how are the fuel injectors ? in my 91 xj my injectors were dirty and i would crank all day long but not fire . i read through my repair manual and i found out that if you hold the gas to the floor and then kick it over it shuts off the injectors long enough to start and then i ran some "lucas fuel system cleaner " through and its been fine since . good luck

Ya I thought about that but kinda ruled it out when I found no power to the ign. coil. But hey definately worth a try

 

[GEEPAHOLIC]

good luck i hope you get it going !

 

[5.0explorer]

Well 1 crank sensor and 1 ign. coil later and we're on the road! Thanks again guys!

 

[rockreligious]

no problem, glad to hear that fixed it.