91 Sunbird- Arrggghhh!!

Back on here with daughter's raggedy-rear 1991 Sunbird LE, 2.2, auto, fuel-injected. I am about to pull my hair out. In brief: bought car August 07, woudn't pass emissions. Repair shop informed me that car had wrong distributor on it, was wired incorrectly, and was tuned up and necessary repairs made. Did pass emissions. Then computer failed. Computer replaced. Then began to die. Computer apparently reset it self and stalling problem ended.

Now...car absolutely SUCKS gas. Fill up, gone in a matter of days. No leaks to be found around fuel tank or in engine. Idles high though. I am absolutely sick. When we first bought this car it ran smooth and quiet and got good gas mileage. Didn't smoke, didn't sputter, nothing. "Fixed" it to pass emissions, now it seems like one thing after another. In addition, transmission is changing hard and late (40-50 mph for second) (Tranny fluid correct color, level, no leaks). I am kicking myself for having any repairs done whatsoever- seems the bozo we bought it from had it going okay, despite his backyard mechanic rigging on most of it.

Any thoughts? I am about to lose my mind. Single mother, not too awfully mechanically inclined. Thank you in advance.

Get it scanned and look for the coolant temp sensor reading cold when the engine is warmed up, for starters. Also check the fuel pressure, not sure if this is TBI or PFI. If TBI should be 10-13 psi. If higher the regulator in the TB could be bad. Lots of other possibilities here, but try and start with the basics.

also check the exhaust for brownish smoke and or gas coming out of it. put your hand real close and sniff.

put some cardboard down under the car on the drivers side from front to back. let it run for a little while and see if the fuel lines are leaking somewhere.

id also note the mileage over a couple days and see more precisely what its consumption is. i put at least 20 bucks in my 93 sunbird and at least 20 a day in my gf's acura legend since my sunbird has been dead. I drive a lot though.