2005 Liberty-Down for count HELP!

[J33pfxGl]

I have a 2005 Jeep Liberty, ran great up until 2 days ago. Drove it to work, ran great, parked it. Went to start it when workday was over and it would turn over but not start, you could tell it wanted to. Checked all fuses, oil pressure was low, but not real low, fuel pump did not click. Assumed it was the fuel pump. We had the Jeep towed, got new fuel pump and installed it. Now jeep starts, but not like it used to, and we have hesitation when we are driving. Step on the gas, RPMs shoot up but no acceleration.

PLEASE Help! Could it be a faulty fuel pump?
Has anyone experienced this?

This Jeep has been the best, I dont know what happend and why so suddenly.

Thanks!

 

[Marlon_JB2]

Check engine light?

 

[Doublecardan]

+1 on the service engine light, what you were originally describing I was thinking, a faulty security system. They may have installed the pump wrong. But what really confused me was when you are describing rpm increase but no aceleration. This is probably a different problem. Is it Auto or Manual. Can you post more info, or at least codes if available and from what you are describing, you should have something in there.