I have read a lot and got some responses to a previous post about this problem but still have not been able to fix my problem. Would the fuel pump be at fault if it lost pressure after reading on the gauge what spec is supposed to be? I just need to know before I drop my tank for no reason. ANY

 

anybody?

 

You mean it reads correct pressure at idle but drops off as you load the engine up (driving around, going wide open)? Could be the fuel pump, partially clogged fuel filter, kink in the line somewhere or inadequate voltage to the pump.

Also, on a non-running engine you will see whatever pressure you set the regulator at- say, 43 PSI, but it will drop off as soon as you fire the motor becuase the regulator is also vacuum referenced to the intake manifold (the little vacuum line that goes to the regulator). That fuel pressure drop-off is normal and how the system is designed to work.

 

I just replaced the fuel filter (easy fix). INFO - Not running-shoots up to about 50, but then drops to 0 within a couple of seconds as soon as the pump stops. Running-stays at about 40. My question really is, if the pressure from the pump drops at all while motor is not running, it there a problem with the fuel pump? Before this happened, for about 4-5 months, the fuel pump was getting louder and louder and sometimes when the tank was low on gas, the engine started to miss and it would sometimes stall out. Once I filled it up with gas, no problem. what do you think?

 

Could be.... Could also be injectors leaking down or the regulator. You can narrow it down by crimping the feed hose under the hood (after priming the pump of course). If pressure holds, then the pump or pulsator is to blame. If not, then it's the injectors or regulator leaking down.

 

Thanx for your reply. Would the drop in pressure at the pump be the reason why the car misses so badly, even if the pressure maintains a solid 40+ while running? Again, i want to make sure it is so I do not drop the tank needlessly. Thanx again.