Sheikh Waqil

Hi, I have a 2001 Camaro z28 ls1 automatic transmission and it has been stalling on me lately when I slow down or come to a stop. I have had the car for 10 months now, and the problem has been off and on. But recently, for the past month it's been doing this very frequently. Sometimes when I just start my car and I need to back up, after I put it on R it dies. But if I quickly rev it on R and then quickly put it on N then it does not die. Same thing happens when I am about to come to a stop or slow down, it wants to die if I am in gear but if I put it on N then the engine kind of revs up and does not die. My check engine also comes on every now and then, but I have replaced everything that the codes said. I replaced the 2 primary O2 sensors, 2 knock sensors and the Throttle Position Sensor. But the check engine still comes on sometimes and the codes are the same. This problem is getting very annoying because, if I am in a parking lot and I need to back up then it sometimes dies when I put it on R. So i have to start my car up again and rev it on P and then put it on R hoping that it won't die.

The car has volant intake, no cats, magnaflow muffler with the tail pipes cut out, and possible a mild cam. The reason I say this is because a lot of people told me that my car might be cammed cause of the way it sounds, but well I don't know how to check if there's a cam.
Also sometimes my car idles funny at idle, sometimes it's normal. What I mean by this is at idle my car might rev a bit, and sometimes it's just normal.

Anybody has any idea on what seems to cause the problem?

PS, I replaced the fuel pump when I bought the car and recently I also replaced the alternator.

codyvette

iTrader: (24)

I am not trying to be a smart *** but it does not sound like you know enough about cars to begin to try an internet fix. The code reader at Oreily is not the same as a good diagnostic tool. I am guessing this is why you wasted your time changing O2 sensors,TPS, etc. Sometimes it is much cheaper to take it to a good shop. Of you can't tell if it has a stock cam or not you are going to need some more experience to repair it with any efficiency. If you are stuck on trying something yourself, try very hard to find a vacuum leak. These usually occur in the PCV system.

chrysler kid

iTrader: (14)

You have a vacuum leak or exhaust leak. Knock sensor codes typically just say the car is running leaner than the computer expects. Throttle position sensor going off because there is air getting in the engine with throttle closed.

My guess is the intake manifold gaskets are leaking

Torch Rot Z

Without checking the car out, were all just guessing here. But my vote is on vacuum leak as well. A local shop may charge 125-175 for a diagnostic check....but will probably save you money in the end.

Circle-D_Brian

I would make sure the torque converter lockup solenoid is working properly. It sounds like the lockup clutch is being applied and not released. The hanging idle could be a vacuum leak like stated above. You may have a couple things going on.

-Brian

chrysler kid

iTrader: (14)

For some reason. I was thinking volant is the sheet metal intake manifold, anyways check your pcv hoses and make sure the intake manifold bolts are torqued correctly and the throttle body bolts are also torqued to spec

Sheikh Waqil

I got the intake manifold gaskets replaced along with the knock sensors. Knock sensors replacement did help the car's performance. Before the knock sensors were replaced, if I would go full throttle the car would shift from 1st to 2nd at just under 5000 RPM. But after replacing the knock sensors, the car shifts at 5500 RPM instead. Also, from a roll if I got WOT the transmission doesn't shift down on OD or D, hence the acceleration feels very sluggish. But if I shift down manually then it does actually shift down and go fast in WOT.

Any tips would be greatly appreciated, thanks.

Sheikh Waqil

You are absolutely right, I am a beginner and I really don't know much about cars. The only things I can fix myself are the headlights, tail lights and signal lights lol. My friend replaced all the sensors for me based on codes given by diagnostic tools from O Reilly's/Autozone. But I even got the check engine light checked at a mechanic shop where they used a very expensive diagnostic tool, and it pretty much said the same thing plus something regarding spark plugs. My friend is my primary adviser for my car, plus I try to get ideas from other people/mechanics.

You are probably right about replacing the sensors for the most part, but Knock sensors replacement did help the car's performance. Before the knock sensors were replaced, if I would go full throttle the car would shift from 1st to 2nd at just under 5000 RPM. But after replacing the knock sensors, the car shifts at 5500 RPM instead. Also, from a roll if I got WOT the transmission doesn't shift down on OD or D, hence the acceleration feels very sluggish. But if I shift down manually then it does actually shift down and go fast in WOT.
I believe that the transmission itself is fine and I even had mechanics drive my car and tell me that there's nothing wrong with the transmission. But then again, the car is inconsistent in it's shift points and this depends on the mood my car is in. Especially when my car idles funny, the car sometimes shifts gears faster/slower than it's supposed to.

I really don't know what's up with my car, and why it is so inconsistent. I mean, at times it is driving so smooth and then another time it starts acting up. I just recently got the AC fixed, and as feared, with the AC running the car wants to stall even more now. I always put it on N when slowing down while the AC is running, even then it stalled a couple of times on N(while coming to a total stop from a very low speed). So now I am very cautious when the AC is running, and I rev it a little bit when I have to put it on N.
Just yesterday in the afternoon with the AC running my car was really wanting to stall in gear and even in N, but when I drove at night time with the AC running it barely wanted to stall and was driving smoother. This is what I call INCONSISTENCY.

Do you know anybody with expert knowledge on these issues in the Houston area?

Thanks.