I changed the fuel pump on my car today and it wont start. I checked the fuses and all the connections. I out direct power to the pump and it turned on. I tried to run the pump with a switch just to get the car to start and it would start but only for a second and then it would no longer start. If I wait awhile it will start for a second then quit. Im not sure what is going on but any and all suggestions would be appreciated.

 

Did it start with the old pump fitted?

 

Check the fuel pump relay on the firewall.

Double check your wiring at the tank/pump...Tan=pump power, black=ground, purple=sending unit

What kind of oil pressure do you have? That relay is also wired thru your fuel pump relay...oil pressure too low, no power to the fuel pump relay.

 

If the car is cranking, but wont start.. Id check fuel pressure.

I did this when I first did a fuel pump swap on a
F-body. The auto parts store gave me the wrong
fuel pump (18-20PSI TBI fuel pump) and It looks
identical to a Tuned port pump.. but with a weaker
flow rate.

TPI motors need 45-50PSI to even function.. Id check
there before you tear your car apart again.

My car would not stay running, and even backfire
inside the combustion chamber at one instance.

You might also want to check your coil/grounds
and distributor for proper operation, sometimes
you can rub something loose back there.