Would anybody be nice enough to take a look at a Datamaster file of my 383 idling in Closed Loop?

It's running great overall, but idles rich enough to smell pretty pungent, especially in a convertible with the top down. I hate gassing some poor dude on a bike behind me at a traffic light.

Anyway, the file is only about 110K and is just of the car idling in CL. If anybody would be kind enough to take a look, PM me and I can email it to you. If that is not cool, I will find a place to put it up and send a link.

 

I have two questions. What size injectors and who tuned it? If you can put it on one of the free sites i would be glad to look at it.

 

Stock injectors at this point. Tuned by G-force here in Houston. Tune runs great, but idles rich.

Here is the file link:
http://www.mediafire.com/?6cjj21ntemm

Thanks in advance for having a look.

 

Hey with an over lap in the cam and the amount of fuel you need to keep a deep breather like a 383 going, the tune has enough fuel keep you running well but alot of unburnt fuel will get by into the exhaust and you wont really see a rich condition because the o2s are only looking for oxygen it they dont care if its burnt fuel, or unburnt fuel in there with it because its only looking for the absense of oxygen or presents of o2. do you have a cat still....Im thinking about throwing a magnaflow high flow cat on mine for the exact same reason, and a E cutout in the future for those 5% of the time when I really need that much flow....

 

Knock sensor is setting a code, causing minor amounts of knock retard almost full time.

Long term fuel corrections (BLM's) are elevated to 136-152 on the left bank, and 140-155 on the right side. Its adding a lot of extra fuel, in response to what the O2 sensors are reporting as a lean condition. If the end result is an engine that is running rich enough to smell bad, its fuel the engine doesn't need. Appears you may have a "false" lean condition, caused by something that is affecting both banks of the engine.

At idle, the right BLM is close to max allowable value, while left bank is at 140. In Cell 10, it reverses and the left bank is at 152 and the right bank at 144. You have to find out what is causing the O2 sensors to tell the PCM the exhaust is lean. Look at:

-exhaust leaks before the O2 sensors
-misfires
-faulty O2 sensors
-exhaust valves not closing fullly.

If it was just at/near idle, the cam overlap would make it run rich, as outlined in the post above. But since its running rich all the time (according to your nose), and the BLM's are elevated in all the cells that you recorded..... although you said it was just at idle, it appears you were driving around for over 3 minutes. The MAP at idle doesn't seem to indicate a huge cam, either.

You might want to ask the tuner to look at the file as well.

 

Seriously appreciate the feedback and info, guys. I'll check a couple of things and get back.

Also, the car was just idling the whole time. Weird where one spike shows a blip in the speed, because the car never moved.

 

There's way more than a "blip" in the speed.... there's 3 minutes where you were opening the throttle, and both RPM and MPH were increasing in a logical manner, engine was operating in Cells 6, 10, 17, 18, etc. If the car wasn't actually moving, it would be the most unusual log I have ever seen in the many 100's of data logs people have sent me or asked me to look at.

There are numerous spots where the "data error' flag flashes red.... that where you see oddball spikes. Is it possible you have a bad connection on the ALDL connector, or a high voltage wire too close to the data wire? Seems like a frequent problem with the Datamaster logs people have asked me to look at recently.

 

DOH!

I was linking to the wrong file. The Idling file is now the correct one in my post above.

Late night posting is my only excuse.

 

 

I completely understand. You help a ton of people on this forum, and I wasted your time with a bad link, though at least the other datalog was from my car, just not idling. I apologize.

Thanks for the initial info, anyway. Good food for thought in isolating the issue(s). I'm a smart guy, and I'll figure it out eventually. On forums about my area of expertise (audio), I'm the "Injuneer" so to speak. Kind of weird feeling to end up as the dork on the Camaro forum.

Oh well, at least it will keep me humble.

Thanks again, sincerely.