Hi I'm new to the forum I recently purchased a 1998 Dodge ram Cummins Diesel N6 and have learned alot about this truck it is a salvage truck, it has a 1998 chassis but the rest of the truck is a 1999 Ram 2500, it has a fuel tank of a 1500 Ram. I'm making the best of this truck as I go. The dealer was selling it for 8000.00 but my wife & I got it for 3500.00 put a new computer and transmission relay in it and the truck ran fine, but the we started having other problems arise, I replaced the speed sensor, and then another problem. I don't even know if the external plug to the glow-plugs even work, I'm having a major problem with truck running down the road and the truck slips in & out of OD and the RPM's going back and forth and even drops out to zero, but pops back up to position. I have read in two different manuals to check the TPS for the problem, I was told you can clean the contacts and reprogram the unit. But I don't know what to do or where to start, this truck is now my project truck to restore the broken items on it. I love the truck just need some guidance on what to do. Please help!

 

Replace the throttle position sensor. They aren't that expensive.

Gas tank out of a 1500? The oil burner never came in a half-ton truck..... not sure if the tank is any different, would make sense that just the fuel pump module would be the only change.....

If your tach is reading strangely, that is a separate issue, and is probably contributing to the trans gear-hunting problem. Fix the tach issue first, see if the other problems don't disappear along with it.