Engine/Transmission (1998.5 - 2002) tachometer jumping, then doesn't read

[RCARON]

i have a 2000 2500 automatic. 170,000 miles, with edge ez timing box. my tachometer started jumping yesterday. i noticed that it does not matter if the truck is cold or warm, the tach reads fine then it just drops off to zero and stays there. after a while it runs fine again. at the same time, when the tach is acting up, and i am slowing down for a traffic light, of just idleing, the truck runs very rough, and twice it stalled, almost like the timing is off. i checked all the connections that i could think of but nothing has improved. the engine light is on but the code i read with the odometer screen is p1693.

the truck always starts o. k. sometimes the engine light does not come on and the tach is reading fine. sometimes the engine light is on and the tach is reading fine. i run this truck every day at least 200 miles.

does anyone have any suggeations?

thanks in advance for your help.

 

[Turbo Tim 1]

Cam or crank position sensor depending on what the 2000 trucks have. The 2001 have a cam position sensor

 

[fj40dave]

Sounds just like what happened when my Cam Position Sensor failed.

 

[csutton7]

yep that should be it--chris

 

[TPlasek]

This is a cut and paste from my old thread. .



https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=72104&highlight=tach







I went to the Cummins dealer and asked for a Crank Position Sensor for a 2000 Dodge. The part number was 4002066 and the cost was $37. I installed it in the truck and since the starter had to come down, I found this a good time to install my new Larry B Super Contacts inside the starter. With 107,000 one side was almost gone.



After install the tach once again worked like it should. .

 

[RCARON]

thanks for your help. i replaced the cam position sensor on thursday night, which did not solve the problem. i replaced the crank positions sensor on friday, and all was well.