does anyone know here what would cause my car to buck and backfire ? it started at just high speeds but now it dies at low speeds and back fires louder then a shotgun lol i have changed the plug wires and plugs, rear o2 sensor, gas lines, fuel filter, oil filter, oil change, the engine light use to always be on and now its off and wont come back on. I really dont know whats wrong and no garage can tell me.
it bucks like its out of gas, and even with a full tank.. I can tell when its going to do it bc i can smell the gas like 15 secs before it happens, its extremely hard on gas , 30 mins = 1/2 tank !!!! ( going 120-160kmh mind you ) please, someone must be smarter then the mechanics down here, some said it was all the things listed above but i already spent 400 so far with nothing to show but even worse problems...
1 mechanic said it might be the EVAP ?? something in the tank that reads pressure ? he took the gas cap off while it was running and the pressure didnt change on the computer..

its so annoying to have a car you cant drivee !!

I personally think it may be either..

Front manifold O2 Sensor..
injectors
powerpack ( distrubter thingy )
something falty either electrical or gas


thanks for any help..

I read a little more on here, and now im thinking, its quite possible its the fuel pump... ill have to listen to it when it comes on at home and see if thats it, it always smells of gas right before it starts bucking, only mods i have is a cold air intake, and fart can which ive had for a while now, its only been doing this for 2 months or so,

and for some werid reason my battery doesnt work anymore good at all, i need boots, and when i crack on the gas my stereo shuts off :s.... or take a corner.. i checked the connections are there tight ??

i really dont know whats going on with this car.. !!!

So you're smelling gas while driving down the road? I'd suggest looking for a fuel leak.

2.2 97 Cavalier......the "Crapalier"

If you've having to boost the car to start it, and the stereo shuts off when you "crack on" the gas, then you need to get your battery problem solved. Under heavy load, the PCM may shut off the alternator to make more power available, which will cause your voltage to drop to whatever the battery is capable of. If its output is less than what your stereo is requiring, then it may shut off. Low battery voltage will also cause the PCM to go into a low battery run mode, which will lengthen pulse width on the injectors (to compensate for lower fuel pressure), and also lengthen the dwell on the ignition coils - and depending on what the current power requirements from the engine, the coils may not be able to provide sufficient spark. This MAY of course cause some misfiring and unburnt fuel - which you're probably smelling largely due to your modified intake.

Solve the electrical problem (or replace the battery if needed) and your problem may go away. There's also a possibility that your stereo is drawing so much current that you're starving the ignition and fuel systems of necessary power - adding to (or creating) the problem.

Just my guess...
John

Drove the car for the first time in a while today, boosted it.. and now it seems to be working fine.. i tightened the battery terminals up, there was a bit of slack there, I bombed around town for a bit and stereo didnt shut off once
and the car hasnt jumped or skipped.. ( usually does it on the highway at speeds over 100km ) so will see how it works out..