I have a 2002 ram 1500 4.7 ,I ha e a crank but no start issue.. no codes.. I have changed the wiring harness,cam,crank,temp,oil pressure sensors,new injectors,new coils. Ecm has been checked and is good. Engine has been rebuilt and everything is new ,timing chains marks has been checked multiple times. I have 160 psi of compression across all cylinders.. I have spark in sequence on all coils. However the injectors all spray simultaneously 1 time when you first try to crank the engine and then won't do anything after that .. I have 43 psi of fuel pressure while cranking .. I am at a loss I have rebuilt and worked on many many 4.7s and have never seen this before . Can anyone help? Also the wiring harness has been replaced .

 

Welcome to DF!

I believe the injectors are timed by the cam sensor..... Is the PCM getting a signal from it??

Moving this to third gen ram section for ya.

 

I unplugged the cam sensor and attempted to crank and it immediately threw a code for it,same with crank sensor . . So with that I assume it's working as it should.

 

need to figure out WHY the PCM isn't pulsing the injectors....

 

that would be great to figure out. But after 4 different cam.sensors,2 different ecms,2 different wiring harnesses,3 different sets of injectors and none of it has made any difference it's getting to be very frustrating lol. There is only so many things it could be . I wouldnt imagine there would be anything wrong with the reluctor wheel on the camshaft ,but i guess anything is possible.. I guess I'll pull the valve cover again and take a look . This is the strangest thing I've encountered with a 4.7 so far .

 

I wonder if you have the wrong reluctor wheel for the cam sensor.... they changed at some point. If you got parts for the wrong year, for whatever reason, everything would bolt up, but, it wouldn't work. Still have the old one? Compare it to the new one.