2nd Gen Non-Engine/Transmission tach problems

[slomodiesel]

my nephew's 1998 1/2 ram has been having tach troubles. as he's traveling down the road every so often the tach falls to zero and the check engine light comes on, a few seconds later it returns to normal, but the check engine light stays on for several miles. anybody know what we should check?

thanks

 

[DavidC]

Crankshaft Position sensor. It is behind the starter and starter removal is necessary to change. It is available at hoeslidiesel.com among other places.



Dave

 

[jdross440]

On my wife's 2000 truck it was the cam sensor located below the injection pump.

 

[analog]

just had this happen in my 2001. I have the Cam sensor that jdross440 refers to rather than the crankshaft sensor. I put in a new one, and the problem went away. It is not easy to do. I pulled my vacuum pump in order to get to the sensor. I think Cummins or Dodge switched to the Cam sensor from the crank sensor in later years, so you may have the crank sensor. Which, to my understanding, is much easier to replace.

 

[jdross440]

My wife's 2000 has both the crank and cam sensor. I just replaced the crank sensor when it was intermittent starting (would crank but not start). The crank sensor through the ECM turns on the VP44 fueling valve.

 

[slomodiesel]

thanks guys, I'll tell him

 

[slomodiesel]

Changed the crank sensor behind the starter and everything fine now - Thanks to you gentlemen! Keep up the good work!