Two days ago while driving on expressway I noticed a little resistance around 50 mph almost like I had a governor on my truck later that same day came to a stop light an truck shut down I start it back up try to pull off it shut down again start it one more time an pulls off fine. Next day take it to shop mechanic check the pressure an check for any codes nothing tells me it sound like the beginning of a bad fuel pump. He told me to drive it an wait to see if maybe the engine light come on. So next day I'm driving on expressway same resistance around 50 mph but can still get it up to 70 once i get off and start to stop at alight cars shuts down tried starting like 5 times keep shutting back down when i try to accelerate I wait about 20 second start it an pulls off fine make it home a park. Is it a bad fuel pump or what?