My car randomly dies after about 5 minutes of driving. And won't start up until a few hours later. Before I found out I had a coolant leak which sprayed the opti so I replaced the hoses and the car ran fine for a while. The opti was changed about 500miles ago after I found the coolant leak into the opti. I was told that it could be the fuel relay. My fuel pressure was fine when I tested it. When the car dies and I try to start it sometimes I dont hear the fuel pump prime or it only primes for a short time ( compared to how long it usually takes)