Hello all, I own a 2000 cavalier and have been having issues with the engine bogging out when i accelerate. Ever since i bought the car i have had to press the gas pedal to the floor when starting, but it starts each and every time, this may or may not be related to it bogging. About two months ago i started to notice when i am driving if i press the gas it seems to have a hiccup and then it takes off just fine. it does it mostly right after i take off from a full stop, or when i'm on the highway. If i let off the gas it stops and runs normal. I first put a bottle of fuel treatment in it but it didn't help. I have taken it to two local mechanics who have both ran full diagnostics on it and and its not shooting any codes. The first mechanic cleaned the catalytic converter and the second cleaned the throttle body and MAF sensor. I am at wits end with this thing and don't know where to go from here. Each time i take it to a shop, they are just charging me an arm and a leg for not fixing my problem. If anyone has any input i would highly appreciate it.

You didn't mention which engine you have, but your problem sounds almost EXACTLY like the hard-to-diagnose problem that I had with my 1996 2.4L Cavalier. I tried many different things to fix the problem (because I assumed as you and your mechanics appear to have assumed) that it was fuel, air, or sensor related) but it turned out to be a failing ignition coil housing-- which made absolutely no sense to me until after I did a bunch of research. You might want to check out my thread from when I was having the problem. You can see all of the stuff that people suggested and I tried (but didn't work). And then in the latter part of the thread you'll see an explanation of how I fixed the problem by replacing the ignition coil housing, coils, & spark plugs. I provided step-by-step instructions and information about buying the parts cheaply online. (It's a pretty easy job.) There is also a link to an article that explains why the problem only happens upon acceleration.

If, after reading the aforementioned thread, you think that this is your problem, I'd recommend that you fix it ASAP, before the housing gets any worse, because once it fails, the car will misfire, and once it starts misfiring, it can quickly burn out the catalytic converter by sending unburned fuel into the exhaust system. If you live in a state that requires smog-checks then you'll have to fix your catalytic converter (~$400). So a stitch in time saves nine.

http://www.j-body.org/forums/read.php?f=11&i=166066&t=165871#166066

All right, im still completely lost. i have the 2.2 non-eco. since my last post i have changed plugs/wires and changed the coil packs. i have put in a new fuel filter, i have put in a new crank sensor. a new timing chain/tensioner. i beginning to believe it may be my ECU. Any help is appreciated.

Possibly could be IAC sensor.... or maybe an o2 sensor... just an idea

Throttle position sensor...

The #1 piece of evidence that points to it is that you have to have the throttle opened to start the car.

The second hint is that it only happens when you are taking off which tells me your TPS has a flat spot. If you were to test the voltage on it I bet you that it isn't linear as you open the throttle.

Replace that sensor, leave the battery unhooked for 15 mins and your problem should go away.

-Chris-



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