Hey guys new to the Forum. Recently my 2005 Impala 3.4 V6 has had some issues with starting. It cranks and doesnt fully start sometimes, other times not an issue starts right up. I replaced the fuel filter, and I can hear the fuel pump priming on when the key is in the on position. There are no issues with power or stalling while driving. Any thoughts or ideas are appreciated.

Thanks much,
Adam

Does this happen with a hot start, cold start, or both? Start with testing your fuel pressure. Just because the fuel pump is on doesn't mean your getting full pressure.

how many miles

Both hot and cold starts, but doesnt always do it. 59000 miles on the impala. What is the best way to test pressure? Take it in to a shop or buy the pressure gauge myself?

Pressure testers don't cost much, check harbor freight. By the time you pay a shop, you could buy the gauge and test it yourself.

Typical FPR (Fuel Pressure Regulator) failure mode. At that mileage, they're usually leaking. Pull the vacuum hose off and check to see if you can see or smell fuel residue. If you can, it'* bad and needs to be changed.
I've heard from several techs that it'* the alcohol they're putting in the fuel that causes them to wear out prematurely.

Thanks for the help. How hard is it to replace the fuel pressure regulator on this year Impala?

Disconnect the fuel pressure regulator vacuum line.
Remove the fuel return pipe from the fuel pressure regulator.
Remove the fuel pressure regulator screw.
Using a shop towel to catch any spilled fuel, lift and twist the fuel pressure regulator in order to remove the fuel pressure regulator from the fuel rail.
Remove the retainer and the spacer bracket from the fuel rail and discard.
Remove the fuel pressure regulator inlet and the fuel return pipe O-rings and discard.
Inspect the filter screen for contamination, if contaminated replace the fuel pressure regulator.


Lubricate the fuel pressure regulator inlet and the fuel return pipe O-rings with clean engine oil.
Install the fuel pressure regulator inlet and the fuel return pipe O-rings.
Install the fuel return pipe to the fuel pressure regulator.
Install the new retainer and spacer bracket into the slot on the fuel rail.
Install the pressure regulator to the fuel rail. Tighten
Tighten the engine fuel return pipe nut to 17 N·m (13 lb ft).

Install the fuel pressure regulator screw. Tighten
Tighten the screw to 8.5 N·m (75 lb in).

Inspect and verify that the retainer and spacer bracket is engaged in the slots in the fuel rail. Grasp and pull on the regulator to ensure that the regulator is properly seated.
Connect the fuel pressure regulator vacuum line.

Adam first you need to do a fuel pressure test a bit different. You do not want to see if you have pressure but need to see if the pressure holds when the engine is shut off. If the pressure regulator leaks back and allows the fuel line pressure to drop to zero the engine will be hard to start. Also I am not sure if the Impala has a check valve on the fuel pump but several models do and the valve will stick causing the fuel line to drain back to the tank. I have had luck before with a good fuel system cleaner with Techron in it (at Autozone or Advance Auto Parts). This tends to clean the valve and return it to normal operation. Never hurts to try a fuel system cleaner first to see if it works.

Also check the vacume lines paying close attention to the ruber fittings. I recentley was having the same trouble and did not think to check the vacume lines. It turned that one of the rubber T'* had deteriated and cracked. Could have saved alot of time and money!