Bad fuel pump symptoms

Discussion in 'Fox 5.0 Mustang Tech' started by 94blackgt 1621, Nov 16, 2004.

  1. What are some symtoms of a bad fuel pump, or a fuel pump that can't put out as much fuel as your car needs.

    Right now I basically have long tubes, a trick flow street intake, and pulleys, and I ported out my stock heads a little.

    My car out of nowhere started popping under load and hesitating. Could this be from a bad fuel pump?
  2. may want to look into bigger injectors and a fuel pump..I got a 255 pump because my car is starving..I go through a 1/2 tank of gas in 2 days...
  3. I dont think its your FP.
  4. have you pulled codes? do you have a FP gauge you can hook up to monitor pressure?

    two major things control FP - the pump and the regulator. bad regulator will dump too much fuel and make it seem as though the pump is inadequate.

    one would need to provide more info and do more testing to diagnose further (i too would not be jumping all over the fuel system w/o more info).

    good luck.
  5. the 255 fuel pump causes you to go through half a tank in 2 days??!
  6. one can run a 1000 GPH pump - if the regulator is working, fuel consumption will remain the same (you are simply pumping 97% of it back to the tank).
  7. I ordered the fuel pump because all my plugs were white even though my fuel pressure was around 41.
  8. I had this same problem on my buddy's 91 GT. Turned out to be the electronics in the distributor. If you have a spare or know someone who does, drop that in and see if it cures it. It's an easy fix. Why order a new pump if the pressure is fine? Even with smaller injectors it should still run alright, you just won't have the power... your computer adjusts all this automatically. Your AF could be off too. Is your MAF calibrated? The problem sounds electronic related... not fuel. Just givin you a heads up.

  9. Nick, it's been a few years. I hope his car is fixed by now.
  10. Now thats pretty funny! :stupid:
  11. A vaccum leak will cause popping under load. Try running your car with the oil cap off and see what happens.
  12. :)