My 91 Cherokee has the "crank but no start" disease. She died out completely on the highway and left me stranded. So far I have replaced coil, and cps to no avail. I checked all fuses and all are good. now I am checking the wires coming from the camshaft sensor and crankshaft sensor and I have a good ground, I have a good 5v reference from the ecu, but when I test the signal wire I'm getting like 8.86 volts. Is this normal? I have been reading and everything says that there should be 0 volts on the signal wire. Im wondering if this means the ecu is bad. Also im getting a code 54 from the key on-off-on method that going off a chart says it is a faulty cmp sensor. I just don't want to throw any more money and parts at it.

 

Check codes. key on key off method....http://lmgtfy.com/?q=checking+codes+on+91+xj+cherokee#

 

So it turns out that the ecm does send 8 volts to the sensor. The problem turned out to be a bad cam sensor or dist sync sensor.