I have an 86 2.8L Camaro I picked it up for cheap and have been dumping money into it ever since!! So here is the deal I have replaced the cap and rotor, spark wires, spark plugs, fuel filter, air filter, and fuel pump. The car idles rough but once I up the RPMs it smooths out. I have an exhaust leak somewhere, and the service light comes on every once and awhile and then goes back off. The car runs the same whether or not the service engine light is on. Ok so the main problem other than the rough idle is that my car will die when i hit the clutch and roll for a few feet but it only happens every once in awhile during the day. At night it happens a lot more often it seems like the cold night air makes it die more???? Any info would be appreciated.

 

uh, no help? I ran the OBD I codes and got a map sensor error and a O2 sensor error. I have an exhaust leak at the manifold so that would most likely be the cause of the O2 sensor. The MAP could be anything??????

 

An exhaust leak by the manifold would have to be pretty severe for it to have that much of an effect on the O2. I've ran my 3.1 with an exhaust leak for quite awhile and it never triggered the O2 intermittently. Your O2 might be on it's way out. I have a brand new stock replacement if you'd like, I paid $30.00 for it at Pep Boys, but I'll give it to you for $25.00 shipped to your door, if you'd like. I have a used MAP as well, but I don't really like selling used electrical components though, so I'll throw that in for nothing...


-Rob

 

The O2 sensor would not cause it to die though right?? I'm thinking maybe the IAC?

 

A faulty connected O2 sensor can cause similar symptoms, try disconnecting the O2 sensor (forcing open loop), wait for the car to reach normal Closed Loop temperatures (fully warmed up), and see if the problem persists. If it doesn't, it's your O2 sensor....

 

This isn't to say that it's not the IAC, it very well could be either the IAC and/or the TPS sensor as well. W/out the proper tools though to diagnose, it all boils down to the process of elimination. Pulling the O2 sensor's connector to check is just another part of that process....

 

I just replaced my IAC and it is running much better. However now it is idling high it might be my timing or my thermostat is going bad, it seems to run hotter than it should.

 

Again, the process of elimination. The higher idle can be a result of the higher temperature. By the way, did you retract the IAC pintle before installing it back it into the throttle body? Are you sure it is sealed properly? Did you clean out the IAC passages inside of the throttle body? If so, pull the thermostat from the waterneck to allow for coolant circulation and see if the idle comes back down to a more reasonable level. If it doesn't, run a quick vacuum leak test to be sure there are no leaks, especially if you removed the throttle body itself to install the IAC. If no vacuum leaks are prevalent, and assuming you didn't buy a defective IAC from the parts store, I would check the Throttle Position Sensor next at this point in time....

 

Alright well it's back to dieing and idling rough again, my next step is to disconnect the O2 sensor and see if it stops like you suggested I hope that is the problem I am running out of money, and my exhaust leak is pretty bad so maybe that has something to do with it too.

 

Doing this will at least help narrow it down a bit. The air fuel ratio is governed by the ECM through the O2 sensor during closed loop, but in open loop, the air/fuel mixture is in a predetermined state. Pull the O2 sensor (simply disconnect the connector, don't take out the O2 sensor itself though), and see if it smoothes out any....

 

Ok so I cleaned my MAF sensor off thinking that might have been the problem too. I sprayed the hell out of it with MAF cleaner. I went ahead and cleaned my throttle body as well. Now my check engine light is on all of the time and when I shift gears the throtle is none responsive for a short period of time and then picks back up again making my car lurch. Did I mess up my MAF even more? or did I screw up my new IAC when I cleaned the throttle body. I figured it was sensor safe cleaner so......

 

^ If you didn't disconnect the battery before you pulled some of the electrical connectors off, you'll need to reset the ECM. Disconnect the battery for a minute or two, then start the car. The SES codes should clear, and if they don't, scan for codes using the paperclip method....

 

whats the latest on this ? just picked up on the 'worse at night' part - would that be with the lights on ? hence some sort of lack of electric juice problem ???? just a thought.
mafs are sensitive mines running like crap as i have no filter connected at the mo and i dont think the airflow's smooth enough for it to read nicely.
have you ran the car without the maf conected to see what happens?

 

what were the actual code numbers?

 

Alright well I replaced my O2 sensor and I fixed my manifold leak. It turned out that two of the rear bolts had snapped off, i'm guessing when the previous owner tried to remove it. Anyways so far like I stated in my first post I have replaced my fuel pump, IAC, O2 sensor, Spark plugs, plug wires, cap and Rotor, I replaced my TPS connector because it was bad, Along with my MAF connector. However I am still having the same problem! could my timing be off? making my car die when it's at a warm idle but not a cold idle? I can replace my MAF but that is a really expensive route if that is not the problem. Same goes for my MAP sensor. I'm thinking it has to be my MAF considering it only happens at night with the cold air. As for the electrical aspect my lights would dim if it was an electrical problem righ?