I have a 95 Z28 Camaro with an automatic transmission. A month or so ago I noticed my Camaro wasn't idleing right. It was idleing too high and idleing sporatically. I went through asmany of the vacuum lines as I could to try and find any vacuum leaks. I replaced a few different hoses and it seemed to run better until I took it for a test drive and it started haveing the same problem. Now it idles fine for the first 4-5 minutes while it is cold but once it starts warming up you can watch the tachometer goup and down between800rpm-1100rpm. The check engine light was coming on at first but not now. The tranny is also now experiencing severe shifting problems so now it is parked but in the mean time I was considering removing the secondary air and emissions control crap to reduce any oppurtunities for unmetered air to come in. I suspect that the secondary air has a leak in it or could be clogged and I think if I can remove that system without causing ECU problems or any other problems this might fix it. Anyone know about this? If anyone could elaborate on this for me or shed some light on the subject I would be most greatful.

 

The only thing the secondary air does is to blow fresh air into the exhaust manifold when the engine is cold. The pump turns off after the engine is warm. Make sure the throttle valves are clean and closed fully, check the idle control valve. Scan the car and look for retained codes. Check operation of the O2 sensors.The car appears to act bad when it goes into closed loop (warmed up), and starts responding to sensor data. To work on these cars you need a scan tool, not a plain code reader, as you want to look at the data sent back by the various sensors, and check its validity.

 

What are the throttle valves and idle control valve? I don't own a scan tool and I don't have the money to buy one. Are there any other things I could check that would cause this problem? Also is anyone familiar with removing the emissions control system as I mentioned before? I still want to remove that stuff.

 

If you don't have a scan tool, you should take your car to a shop. It will be cheaper than throwing parts at it. You should at least get a service manual, so you know what you are lookin at.

 

I am still wandering about this guys. I have been dropped suddle hints that the ECT sensor going bad can cause it not to idle right. Is this true? The ECT sensor has been bad for a while but I was told it was mainly just used to tell the cooling fans when to turn on and off and I just keep the A/C switched on so the cooling fans stay on.... cheap and lazy I know, but will the ECT cause other problems on these cars? I know in VW's it's only objective is to turn on the cooling fan but this isn't German so help me out if you know.

 

Besides turning on fans the computer uses the ECT data to determine how much fuel the injectors should meter out. So if you know it is bad, you should change it.