1994 jeep 5.4 v 8?

The 1993 Jeep is powered by a 5.2L or 5.9L.

The PCM (powertrain control module)requires a crank signal to run the pump (PCM supplies a ground signal to the ASD relay) . The pump will prime after the key is initially turned to the run position ( apx. 2-3 seconds), once a signal of sufficient speed is seen, then the PCM signals the ASD and the pump is supplied power via the ASD relay. Crank sensors get there signal by producing a magnetic field and create a voltage wave form as the tone wheel (attached to the flex plate) passes thru it, creating a series of square wave patterns, spaced at intervals around the circumference of the flex plate.

There is a high probability that the crank sensor has failed, if you have a hard code indicating a lose of signal.

Bad crank position sensor will cause the fuel injection and engine control module to malfunction. This data is needed for the module to properly coordinate various functions.

my 98 did the same thing. changed it in about an hour and $65.00 for the part and it fired right up.