Hello folks! My friend has a 97 Cavalier 2.2l with 87k on it and it's a never ending source of problems. I'm trying to maintain it on the cheap for him, but this latest problem has me stumped.
Two days ago, it ran fine, yesterday it started to lope heavily at idle, lose all acceleration (won't go over 35mph which is a chore to achieve), dies at stops. I've noticed a strong gas smell from the exhaust. The fuel filter was changed 1-2 weeks ago, tuneup was a year ago( checked plugs/wires seem normal ), spark was good, and NO trouble codes!!! I'm at a loss... I've browsed around and seen suggestions from evap, to timing chain, to fuel system, ignition system, to gremlins...lol
If anyone has experienced this or something similar, I'd greatly appreciate your input... Thanks!

 

Also, in park at idle, if you goose the gas pedal it bogs like its starving for gas initially before catching up and responding to input.

 

My daughter used to have a "Crapalier", and I was the lucky one to have to work on it. What your friends is doing sounds familiar to what we had, but I was getting a random misfire code. After determining it wasn't anything ignition related, I figured it must be an injector. Pulled one plug wire at a time, then started the engine, and found the cylinder that didn't make a difference. Ran a couple tankfuls of injector cleaner, didn't help at all. Pulled the injector and replaced it with a generic aftermarket one (which was a mistake to do), and the engine ran even worse. I finally just soaked the old injector in carb cleaner for a couple hours, swishing it around periodically. Pulled the new injector, put old one back in, and the engine ran like a top. About a year later, went through the same thing with a different cylinder. Not saying that's your issue, but it's something to check out.

 

Yeah, I've actually tried pulling the plugs one at a time and it still affected every cylinder, now of course there is a p0300 code, but that was expected... I even unplugged all four injectors one at a time and same thing...ugh Thanks for your input!

 

I've also pulled the egr valve and it wasn't stuck open or constricted, fuel pressure regulator not leaking...

 

Does it act differently between a cold and hot engine? At 80-some thousand miles, ours had a slightly warped head at the front corner, making the engine act up only after it warmed up. It was head gasket/rebuild head time.

 

Same hot or cold...

 

Never mind! I figured out what the problem was. The tensioner for the timing chain had deteriorated to such a degree that the chain had skipped a couple teeth. Went ahead and replaced the timing chain, cam sprocket, crank sprocket, and timing chain cover gasket. Now she purrs like a kitten, quietest I've ever heard it run. Thank you for the input Camaro 69!

 

With only 87k miles, wow. Glad to help, good you got it figured out.