[RBMann]

I know I am not the normal tuner here. I want smooth running(no surge) and good mileage, not concerned with trying to get more power.

The PC III was installed to try and cure surge with the stock pipes and muffler. The PC uses a wide band O2 sensor. Stock A/F is 14.7 according to makers of the PC. The PC III comes set to 13.8 A/F and some bigger numbers in closed loop cells that it supposedly can't control. Found an article that told how to check a box in the PC software so the added values in closed loop area will be used. I have been making new maps trying to get the stock mileage back while targeting the individual cells to solve surge instead of just dropping the A/F for the whole closed loop area. I have looked at a single cell and increased the value to 50% and then watch the A/F jump as it passes through that cell so it seems that the value can be changed in closed loop. I also have noted that if I add fuel in the idle cell then it becomes hard to start when cold and blows rich smoke out the pipes when you rev it. The A/f reading is very constant at say 3,000 RPMs but not necessarily where the PC is set.

I have tried to work through all the normal stuff sync, valves, timing and air leaks but it seems like some piece is failing. Went back to 13.8 in the PC and the idle is still lumpy. No fault codes found by the dealer. At this time it also has a lot more vibration through the whole rev range but the worst between 3,000-4,000. The vibes are very constant while the lumpy idle comes and goes. They appear unrelated but I don't know. It feels like the timing or sync is off but both check out OK. Maybe a bolt came out of the clutch to cause an imbalance, I just don't know.

At this point work and $$$ are messing with me so I will probably just let it set for a while.

Thanks for the help.