07 liberty dies at startup

[89jeepcomanche]

i have a 07 libby that wont start. i changed the fuel pump because there was no fuel at the rail. after the pump install there is fuel at the rail and it now will fire up but then immediately die. no codes being thrown. please any suggestions in what way i should start trouble shooting would be appreciated.

 

[dude1116]

Will it stay on if you hold the gas? Might be worth checking the IAC (Idle Control Valve).

 

[tjkj2002]

No IAC for a '07 since it's throttle by wire.


Bad battery or chipped key could be a issue.Could also need a reset by taking both battery cables off the battery and touch them together for 10 or so mins and hook back up and try to start again.

 

[dude1116]

No IAC for a '07 since it's throttle by wire.


Bad battery or chipped key could be a issue.Could also need a reset by taking both battery cables off the battery and touch them together for 10 or so mins and hook back up and try to start again.

Doh! Good call. That's why you're the expert. :smokin:

 

[belvedere]

Have you measured the fuel pressure?

 

[Billwill]

As stated by tjkj2002 if there is a problem with the PCM recognising the chipped key then the Jeep will fire up and run a few seconds then shut down.

This scenario usually means the SKIS light on the cluster will flash at you instead of going off after the ignition being switched on for a few seconds.

Fuel filter good?

 

[CactusJacked]

Have you measured the fuel pressure?

Yes this. Just because you have fuel at the rail doesn't mean you have sufficient pressure to squirt through the injectors. Get a fuel pressure gauge on it and check what pressure you have when the pump primes (key on, not start), and what the pressure is at when the engine starts and right before it dies.