i have a 98.5 cummins 3500, it has been acting up by having low power, sputtering and having a dead pedal when i stomp on it, check engine light comes on and sometimes it will completely die. no codes come up and just changed TPS and fuel filter, no idea what it could be but I'm leaning towards my injection pump but would just like to know if anyone knows for sure before buying one, anything would help I'm a little stuck. thanks

 

What's your fuel pressure ?