04 Vibe cranks and will not start, sometimes

[Allen3546]

I have an 2004 Vibe 1.8L FWD that has been a champ to 177k miles. It now has a problem with starting and I will list the problems and what I have done below:

-The engine will crank but will not start sometimes and the fuel pump had no voltage
-Checked the fuses and relays (hood, and inside dash behind mirror adjuster)
-Put in a new fuel pump
-Sprayed engine starting fluid into the air intake and heard the fuel pump engage as the engine ran for 2-3 seconds
-Once the fuel pump engages all is good till the next day, so far
-The fuel pump will work if you bypass the relay and wire it directly from the relay slot to the fuel pump
-Same thing happened on day two and after trying to start it for a while the fuel pump came on once at the end of cranking and then no problems


Anybody else have this problem or any experts on here care to help someone out trying to figure out what is wrong? Also just replaced all four struts, motor mounts, both control arms, and ball joints recently. I know the problem is somewhere in the fuel delivery because It will run just fine when the fuel pump has voltage. Any thing to rule out or look into?

[lannvouivre]

Check the grounds on the driver's side of the engine head.

[jolt]

Fuel Injection Pressure Regulator bad causing loss of fuel pressure when car sits not running. Test fuel pressure, it should be around 45 psi with engine running and with engine shut off. Leave engine off over night and see what the fuel pressure is the next day. If the line does not stay pressurized, you do not have any fuel to start the engine. The regulator acts as a check valve to hold the fuel line pressurized. Another thing that will cause pressure loss on the fuel line as the car sits is a bad / leaky fuel injector.

The fuel pump in the Vibe only come on if the engine has enough RPM's. It is a safety thing - if the engine is not running because the car was in a crash, the fuel line got damaged, and then you surely do not want the fuel pump dumping gas as a fire could start in the crash site.