91' cherokee 4.0 wont start...help!!!!!

[clayfmx]

Ive got a 1991 cherokee laredo 4.0L automatic

It cranks over and acts like it wants to start but nothing.
Ive replaced the cap and rotor, crank postition sensor, plugs, wires. The fuel pump is functioning properly and i am getting 40lbs of fuel at the rail. I also get spark.

After i replaced the crank sensor it started right up. Problem solved??
hell no!! It ran great for about a week then would not start again this morning. I figured napa sold me a bad crank sensor and replaced it again tonight but the jeep still wouldn't start. WTF!!??!!

Any Suggestions??

what are the signs of a bad CAMSHAFT position sensor?????

thanks,

Clay

	Crank position sensor A crank sensor is a component used in an internal combustion engine to monitor the position or rotational speed of the crankshaft. This information is used by engine management systems to control ignition system timing and other engine parameters. Before electronic crank sensors were available, the distributor would have to be manually adjusted to a timing mark on the engine.

[90Xjay]

Anytime I have a no-start that is kicking my butt like that, I go back to basics.

You gotta have fuel, fire, and compression to start.

If you checked fuel pressure and you have fire, is it a good hot spark or weak?
do you have a compression guage to stick in the cylinders and check compression?
I mean, the problem has to be related to one of these categories.

[clayfmx]

so i replaced the relays under the hood. The jeep started right up. I shut it off and it would not start again. This is really screwing me up now!!