Hi my name is ***** ***** I will be happy to assist with this today.In some cases I may need more info to assist better.I apologize for any delay.
Since you were able to replace the fuel pump relay and it allowed the pump to run most likely the fuel pump is drawing to many amps and over time this damaged the old relay.The most common cause is the fuel pump itself needing replaced.Even if you have fuel pressure it may not be enough fuel pressure to allow starting and proper operation of the engine.
What I would do next here is test the fuel pressure.This is done with a fuel pressure test gauge which you can usually rent from a local parts store.The gauge threads onto the test port on the fuel injector rail on top of the engine as seen here.https://www.dropbox.com/s/66oo830gjowrrim/test-01-13.gif?dl=0.
You will then turn on the key and observe the fuel pressure.If the 8th digit of your vehicles VIN number is ***** Z the pressure should be between 48 and 54 psi.If it is any other digit then the pressure should be 55 to 62 psi.If your pressure is any lower then this then the fuel pump is weak needing replaced and the fuel filter should be replaced as well.
The fuel pump is located inside the fuel tank and the tank will need lowered out of the vehicle to replace it.The rear driveline usually needs removed then the fuel filler hoses and then the tank straps then lowered somewhat then the fuel lines and vapor lines disconnected from the tank and pump then the tank removed and the pump replaced.
The cost of the pump will vary depending on where it is purchased at ranging anywhere from around $200 to $500 in some cases.Repair labor from a shop can run around 3 hours charge.
If the fuel pressure was already tested and found to be o.k. let me know so we can continue.
If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service.You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.