2013 Hyundai accent. I was at a stop light and the car just turned off. I tried starting it again and it cranks over but just refused to start. I thought maybe the fuel pump died. I ordered a new fuel pump and replaced it about 4 days later. After installing new fuel pump the car started up just fine. I drove it for two days and it just turned off again while driving it. I didn’t have time to look into at again for 4 days because of work. When I had time to look into it again I tried to just start it up and it started just fine no problems again. I drove it for 2 days and it died again. Same pattern if I let it sit for a few days it will start up again no problem. I’ve tried swapping the fuel pump relay with a different one when it doesn’t start and it still wouldn’t start. When the car was running the fuel rail gauge pressure is about 580 psi and the car was running just fine. When it died I checked the the pressure and it was 36 psi. When I try to start it it stays at around 36 psi and car won’t start. I did notice whenever it seems like it might start that’s when the pressure starts to slowly go up and it gets about as high as 290 psi. Then the pressure starts going back down and it doesn’t start. Does this mean it’s most likely the high pressure fuel pump? What would cause it to only run ok for like 30 min and then not want to start again for a while before it runs again for like 30 min? I have replaced the fuel pump and crankshaft sensor so far. I can’t afford to take it to a mechanic right now. Any mechanics here have any tips at what could be causing this or what I should look into? Thank you, very much appreciated.
Did you check for any fuel line leaks, check for any wiring issues? It is always possible that the new pump that you bought was bad out of the box (probably not the case, but I have run into this with new parts before). There is also a trick with a failing fuel pump, if it doesn’t start you can beat on the tank (without damaging it) with a rubber mallet in the pump location of the tank. Sometimes with failing fuel pumps, this is enough to get them temporarily working again. Don’t get hung up on just the fuel pump or even fuel system, maybe something else is going on. I would try to make sure the wiring to the pump is ok first.