Help needed for NHC 250 in U.K.

[k0337788]

Can anyone help? My Cummins hangs onto the revs after you have removed your foot from the gas pedal. Truck has been standing for 15 years but has been started a few times every year. Want to restore now but has this engine problem. Any ideas?
Thanks fotr your help
Andy London England

 

[WillWagner]

Make sure the throttle return springs are there. Taking air will cause this symptom. I have also seen, 1 time, that after the engine sat for a long time, the throttle shaft would actually stick in the pump housing. With the engine off, work the throttle down at the engine to make sure it is going back to idle.

 

[k0337788]

Thanks Will - will check that out. Seems to get worse as the engine warms up & has got worse since i first bought the truck. Regards Andy

 

[gimpyrobb]

Check for binding of the throttle shaft too, I have seen that twice now.

 

[WillWagner]

If it gets worse as the engine gets hotter it could be a pump issue. Does it start cold OK?