02 Cavalier no start

[mentalattica]

I'm hoping someone can offer some help before I'm forced to visit my local dealership. My girlfriends 2002 (78,500 mi) Cavalier will not start without starter fluid being sprayed in it. The fuel pressure is fine, fuel filter and pump is fine, and the starter, battery and altenator are all in good shape. The car cranks but the engine won't ignite.

We took it to the shop the night before last and let it sit in their parking lot overnight to be sure it wouldn't start in the morning. Just as I said "watch, it'll start up right away when they go to look at it." So the shop couldn't duplicate the no start. She has never replaced her fuel filter since she got the car brand new in late 2001 and the filter was rusted to the fuel line that it screws on to. So we had to get the shop to replace it since I couldn't get it. They also cleaned the fuel injectors.

This morning it's not starting again without starter fluid. It runs perfect after it does start, and does not stall at all. After the first start in the morning, it usually starts for the rest of the day until sitting over night.

I also swapped out the A/C relay for the Fuel Pumps relay so I'm almost certain it's not the relay. I also replaced the plugs about 6 months ago so they should be good. I threw a can of seafoam in the tank and refilled the gas tank with premium grade fuel (we usually use the cheapest stuff from generic gas stations).
And it's not throwing any codes.

Any ideas? Maybe an 02 sensor? I'm just reaching here as we don't have the financial ability to visit the dealership without it really setting us back.

[tkdieter]

My fathers 04 has same problem and also has 78000 miles on it. Do you have the 2.2ecotec motor.