Fuel pulsator

[Guest dpannell]

I've developed a problem with hard starting...It seems my fuel pressure is bleeding off within 5 minutes of shutting down. THe FSM points to a few specifics when this problem develops......kinked lines, regulator, fuel pump, pulsator, leaking injector(s).

My lines are all straight and unkinked....

Filter is new

Pump is 1 year old with 16k on it

Regulator was changed out with a known good one.

Injectors and rail were changed out with a known good one.

so........Has anyone seen a pulsator cause this problem and replaced it?

How readily available are they??? Gmparts direct didn't list one...neither does parts america.

How necessary are they? THe new GM pump came with a small piece of fuel resistant hose and 2 hose clamps. I'm not one who normally deviates from "factory" so I used the old pulsator.

Anxious to hear what you guys have experienced in this regard.......... Dave

[Ronnie]

Below is what AutoZone has to say about the pulsator. They have them for sale. I would also investigate a leaking injector.

AutoZone:<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Fuel Pump Pulsator Operation:

A small accumulator mounted between the fuel pump outlet and the fuel pressure regulator. Most are mounted in the fuel tank between the fuel pump outlet and the fuel supply line. It reduces the fuel pressure variations that occur as the fuel injectors open and close, and to reduce operating noise. Usually built-in grommets seal the unit to the tubing ends. Some are made into a section of flexible fuel line located in the engine compartment. Failure of the in-tank units would result in increased noise or loss of fuel pressure or volume, depending on the type of failure, the external units could develop fuel leaks detectable by smell or visual inspection. The pulsator isn't a routine maintenance item, although replacing the in-tank unit is recommended with a fuel pump replacement. </div></div>

[Guest dpannell]

Thanks Ronnie, Advance carries them as well..$17.89...they just don't have any listed online through Parts America. I've got the tank dropped and heading out the door to pick up a new one and filter. I hope it does the trick. Dave

[Guest dpannell]

Turns out the pulsator was fine....but the check valve in the pump went bad. For kicks I blew through an old round ball point pen I inserted in the top of the pump and pulsator...it blew right through the pump easily. I bought an aftermarket pump and installed it with a new pulsator. The old pump was GM with only 16k.

Dave