I have a 94 Z28 that runs ok whe it is cold but has a stumbling issue after it is warmed up and sits for a few minutes, the the issue clears up. I have a datamaster capture that I can send anyone that will be willing to help me figure this one out!

 

I received your data log. Could you please include somewhere a list of all the mods on the car (if any) that would affect engine performance?

If I understand your sentence above, it starts OK and runs OK cold. Then after it is warmed up (180*+??) it starts to stumble, then after it sits a few minutes it clears up - confusing. I'm not sure that's what you mean?????

Might want to add a "signature" with basic info.

You have a trouble code for the MAF sensor? At some time in the recent past, did you disconnect it for any reason?

Its running extremely rich at idle and WOT (1,000+ mV's), but I haven't tracked down the cause yet. It seldom seems to idle in Cell 16, and when it does, the long term corrections are staying at 128 and the short terms around 127, even though the O2 sensors are over 1,000 mV's and not cycling.

But I need a list of significant mod's, and I need a clearer statement of when the problem is happening.