2013 international maxxforce

truck is shutting off on its own when turning, will stay on going straight down road but as soon as i make a right turn too quick it shuts off on me. and i need to pump fuel to get it started again. Used to start right up and now i need to pump pedal and/or use starter fluid to get it on. one shop told me it may be fuel pump but not sure if it would only cause the shut off on turns. i was thinking if it was pump i wouldnt be able to even drive it straight down road. also loss of power. any insight or help would be appreciated!!!