Was 10 minutes into a road trip with my 1992 W350 when I lost power going up a valley while on cruise control. I let off cruise and power came back until I made it another 2 miles down the road and lost all throttle response with the motor running at a rough ideal. I pulled over to the side of the road and shut the truck off as it was running a bit rough. Before shutting it off I tried mashing the gas pedal down a few times and had a little bit of response when the pedal was pushed all the way down but it kind of bogged out the engine when I did that. Truck wouldn’t start after that, It was dark out so I didn’t try to much to investigate the problem. Throttle cable is still connected but didn’t check too much for frying, but I can’t see that not allowing it to start.

 

Have you checked for water in your fuel filter?

Or it is running out of fuel? Maybe due to a bad line or simply an empty tank?

 

I was thinking possibly air filter but after re-reading it I concur with Oliver on fuel filter being plugged wit water or dirt

 

The issue ended up being a broken wire off of the fuel pump

 

So it has an electric fuel pump on it? how many psi is it pushing? The front seal in your IP will only take around 15 psi or so, any more than that and you risk pushing the front seal out and it will fill your crankcase with fuel

 

My guess is the words "fuel pump" actually mean the injection pump and the FSS wire fell off, or was loose.

Strange that his first post was about how it slowly died and lost power. When I have had FSS wire issues myself, one second the truck is running fine the next it shuts off.

 

My mistake on the wording, it was the injection pump

 

Glad you got it fixed.

 

I had the same issue and resolved it by replacing the slip connector with a ring connector. Never had another issue.