no start on 1996 4.0

[Interceptor9C1]

hi, im trying to figure out a no-start on a 96 explorer with the 4.0. According to the owner, it just had a new motor put in, the belt broke while driving and took out the crank sensor. They replaced the crank sensor and belt but no start, so they put a coil pack on and still no start.

Heres what i got, no codes. Through a scanner i can read an RPM signal for about the first two seconds while cranking and then it goes to zero until i shut the key completely off and then turn back on. With the rpm i lose spark and injector pulse. The resistance of the crank sensor wires are good and the crank sensor has a perfect waveform at it and the pcm. The pcm was also swapped for another.

Now could a cam sensor be an issue here? From what i tried to gather it seems like it should run without a cam signal in basically a limp mode. But will it start without the cam signal? why would i lose rpm which is picked up by the crank sensor in that case. this seems like an odd one

 

[robertoa1a]

It sounds like you have some good test equipment and a book at your disposal.

There is also a crank position sensor and on either there is no way around the trouble shooting listed in the book (Chilton's / haynes).

Read some similar post within the last four pages. The guy with the broken crank had a bad day.