Forum Discussion

cbgalyon's avatar
cbgalyon
Explorer
Mar 28, 2021

1999 Fleetwood Discovery 5.9 275 HP

Our engine light comes on, we have throttle response when idling out of gear, but when the transmission is engaged in drive, there is no throttle response. We have white smoke, and no code on Silverleaf or other readers that we have tried. We have changed the lift pump, the 2 fuel filters, cleaned the map/boost sensor. Checked and cleaned grounds on batteries and frame. Engine starts and idles fine, light comes on after a few minutes running, but you put it in gear, and there is no throttle response at all.
  • My Monaco has some kind of electrical/computer operated throttle. Not mechanical. Once it went to dead idle and I had to reset the computer. Don't explain the white smoke.
  • ferndaleflyer wrote:
    does that thing have a mechanical throttle linkage or is it the one I guess you call computer actuated. White smoke is usually water I believe.


    It's a 24V Cummins ISB, throttle by wire.
  • It is computer actuated. It is a VP44 pump. We were thinking it could be electrical, but maybe not. We got some codes saying low voltage, then high voltage to the data going back to the ecm when we had one TPS on it.
  • does that thing have a mechanical throttle linkage or is it the one I guess you call computer actuated. White smoke is usually water I believe.
  • Still have not found out what our problem is. We have replaced the TPS with 3 different ones, but still get the same thing. The coach will idle just fine and has throttle, but with some white smoke. When we put in in gear, there is no throttle response. There are no codes. We have checked the wiring from the TPS to the ECM, and it checks out good. The check engine light comes on, goes off, then finally stays on solid. This has baffled everyone we have contacted about the coach. Would appreciate some advice on other things we might try.
  • White smoke/no throttle typically means the turbocharger died. limped more than 200 miles in that condition driving tractor trailer on a few occasions.
  • I'm not familiar with the MH Cummins, but that year Dodge Cummins had a throttle sensor on the side of the engine (from the cable operated pedal). It may be bad.