I have a 1994 Camaro Z-28 and have noticed that I don't think that my car is running quite right. I just replaced my spark plugs because I thought that it could be the problem. Well, it seems like when I am in like second or third gear and driving at low RPM's under a load, like going up a small hill, the engine lopes. I noticed using DataMaster that the spark advance graph goes up and down at that point, somewhat similar to a sinusoid wave. Usually it only lasts for a second or two and evens out. Also, I have notice that when I accelerate moderate to aggressively I get spark retard. When I was going about 20 or 30 mph and then basically floored it, I got like 4 degrees or so of retard. When I am going at a steady rpm i don't have any retard, same is true when I accelerate slowly. Is this normal behavior? I am not getting any DTC's. The only mods that I have are the ones listed below.

 

Anyone have ideas on this problem? I am still having it.

I have also noticed on the Histograms that I have a rich condition in both short and long term counts on both left and right sides. The RPM ranges vary, but are usually on the low end, from about 750-2500.

Thanks in advance.