89 RS 305 TBI 178000 miles:
Fuel pump is priming, but doesn't sound like the typical sound, it sounds kind of "sick". What is happening is that sometimes when accelarating normally, after shifting to 2nd it will hesitate a little bit. There was some misfiring but I found a burnt plug wire touching the manifold. I replaced all the wires thinking it was going to be fixed. No more misfires, but still the hesitation. It goes away when you give more gas or let off the gas. I checked the plugs and other ignition components. All are good and only have been used a few thousand miles. There were never any codes, even when it did misfire. I do not have a way to test the pressure right now. The fuel filter was changed a few thousand miles ago too. Idles fine in gear without any bogging or stalling. I run fuel injector cleaner now and then. Sometimes 1/3 to 1/2 can of seafoam. Injectors are good and spraying their cone shapes. The TB has been off and cleaned very well last year. Gaskets are new and no vacuum leaks.
Do the pumps start getting weak before failure or is it a work or no work thing?

 

all possible variations can happen to a fuel pump... but usually they will get weak And louder... before they burnout... but sometimes even with a new aftermarket replacement your driving for 2 weeks and it dies.... A FP tester is a must there cheap....

 

Should I use a fitting like pictured that goes in place of the fuel filter to test the pressure? I would think it's better to test at the throttle body with a different fitting.