Tach not working at low RPM?

[johnkracing]

Been a while since I've been on, I've got 94 idi turbo and the other day the tach stopped working at idle. Then I noticed at low rpm cruise the tach would intermittently quit and I could feel a drop in power. If anyone can give me a starting point where to begin searching for a cause it would be appreciated

Thanks in advance

 

[Golden Helmet]

Is your truck an automatic? If the tach stops working the transmission will start acting funky, but if it's a ZF-5 it shouldn't care at all.

As for the problem, it sounds like it's the tach sensor. It's that big sensor right next to the oil fill cap on the timing gear cover. Check and see if you can see any bare wire, if you can then that sensor is done. It can still be bad even if the wire looks good though, mine started doing the same thing as yours and the wire looked good, but I replaced the sensor anyways and I haven't had a problem since.