celtuckian

I have a '94 Grand Cherokee Laredo with the 5.2L. One day it decided to be difficult to start, but finally did after cranking for a while. Then things were okay for a couple of days and then it did it again.

It was acting as if it was a fuel pump, but since I had just filled the tank and didn't to fool with dropping a full fuel tank, I decided to first make sure something else wasn't wrong.

Long story short - I get spark to the distributor, but I do not get spark to the plugs. After several searches on here and reading several posts about similar problems, the following items have been replaced:

New distributor cap
New rotor
New crank position sensor
New coil pick-up/cam position sensor (whatever you want to call it)
New spark plugs
New fuel filter
New timing chain and gears
Checked Automatic Shut-Down relay (it is working fine)
Checked relay to fuel pump (it is working fime

Now for the questions...
What should fuel pressure at the rail be when the ignition is turned on but engine not running?
How do you check a crank position sensor to determine whether it is functioning properly or not?
How do you check a coil pick-up/cam position sensor (again, whatever you want to call it) to determine if it is functioning properly?
Why will this thing not start?

Sorry for the long post, but I am chasing my tail and having no luck.

Thanks,

94zjdriver

I had a simular issue with mine.. would stall and then run good for a couple of days. then stall agian and run good for a couple of day... finally got to the place it would hardly get out of its own way... put in new fuel pump... like new again.. just saying.

ol"blue

To check the crank sensor:

celtuckian

Thanks, Ol' BLue. This will definitely prove helpful.

As it turns out, I finally conceded to let the local mechanic take a look at it as I didn't have the time to do the diagnosis, nor the inclination to stand out in the rain (I have no garage).

The problem ended up being the coil. It had enough juice to create a spark at the distributor cap, but not enough to push it through the remainder of the electronics, etc. to the spark plugs. Very frustrating (and expensive, by the time I replaced all the aforementioned parts).

But...problem solved. Bad coil.

ol"blue

Oh well, glad you've got it running again.

Bustedback

You're good for another 100k now.