So I have a ecotec motor in a 04 cavalier. Since I've purchased this car a few months back I've been having a problem where my engine acceleration sticks between 1000-2500 RPMs. Sometimes when shifting into neutrual to come to a stop or coasting the car about drops to .400 RPM and bounces back up to 1500 RPM and down to 1000 RPM. Let me state this isn't a RPM gauge problem but the actually engine is reving and then almost dying. I also notice it's worth when I have my heater or air cranked. This can actually cause the car to die.
The things I've checked and have done are listed below.
- Cleaned Throttle Body
- Clean IAC
- Checked for sticking acceleration cables
- Checked for sticking pedals
Look for small black rubber hoses that may have come off some fitting....
vacuum leak around your intake gasket...i had the same problem as you....if i gave it gas and let off at idle it would stall out....check that and let us know...check all your gaskets....if you took some brake cleaner and sprayed around all your gaskets it will idle normal for a second and you know where your leak is .....because it sucks it through the system....no it will not hurt your car. you go to a shop they do the same thing and charge you 60-100 bucks an hour. Do you have a check engine light on?
"If you have no clue what's going on... STFU!"
This reeks of dead IAC valve.
Vacuum leaks will cause an irregular high idle, but it takes a lack of air to kill an engine.
2002 Cavalier 2200 5spd
that it could be... i thought he changed it, but he only cleaned it...good possiblity....still leaning towards vacuum leak though, mine bounced up and down because i had a hole on my intake manifold went from about 600-1500, and back down it would bounce back and forth, and once i accelerated it would stop, untill i got off the gas.... Keep us posted as to what the problem is....
"If you have no clue what's going on... STFU!"
my civic rev'd itself when the tps was bad. Not sure if gm cars would do the same or not?
I had the same problem.........my problem was too low of fuel pressure so i repalced the pump.........helped some but the real problem was a bad ground wire to the O2 sensor
do you have any CEL codes? Could be a multitude of different possibilities. If you have a voltmeter, you can check your o2 and other sensors to see if you're getting a good signal to the ecu. I'm fairly certain I've seen a data chart on here somewhere with voltage references for the different sensors.
Or, you could dish out the usual $80 bucks and have a shop do a diagnosis on it for you.
Jason
I experienced the same problem for a few months...turned out to be the throttle position sensor, might wanna check that
I'm leaning towards the throttle position sensor too.
I have no codes on the dash. The car idles fine once I'm completely stopped.
I had the exact same problem about 6 months ago and what a PIA to diagnose. I checked EVERYTHING over and over and the problem ended up being a broken electrical wire near the PCM in the fender. The broken wire routed from the PCM to the IAC valve. I have no idea how or why the wire broke, but I spliced it back together and the problem was immediately solved!
I would say its a vacuum leak carefully check all the vacuum lines coming off your tb and good luck
