7.3 IDI rpm’s climbing on their own after 2500

[TristanH89IDI]

1989 N/A 7.3 IDI. Starts first crank every time, runs great, no blow by. Up until I hit about 2500 rpm, once I hit that the rpm’s climb on their own without any more throttle to about 3000-3200 then sits there. And has light black smoke while doing so. I eliminated air intrusion so it’s not that. I’m at a loss other than the injection pump being worn out. Any help would be greatly appreciated

 

[DougBoy66]

Are you loosing any oil. Not sure how easy it could injest the engine oil without a turbo but that would be my first thing I would try to eliminate. Just because if its burning engines oil it could kill itself pretty quick

 

[DougBoy66]

Curious, how do you shut it down?

 

[TristanH89IDI]

It doesn’t run away, it climbs to around 3200 rpm then doesn’t go any higher. I can give it more throttle and it will rev to the governor like it’s supposed to

 

[Black dawg]

Do you have another pump you could try the return fitting from?

 

[TristanH89IDI]

Do you have another pump you could try the return fitting from?

What do you mean by return fitting? Do you think issue lies in not being able to return enough fuel?

 

[Black dawg]

The fitting on the return outlet of the pump is what regulates the housing pressure in the pump. I have seen them run just like you describe if that valve is stuck open or bad.