Originally posted by clmbia45
This is a case where I can never get it adjusted on the bench. My thoughts follow. If you do the "pinch" test and squeeze slowly, the idle rpm should increase as the engine leans out. If it doesn't, you're too lean. Knowing that you're too rich, lean the LSN until the engine just increases in rpm and runs at idle. You will have to decrease idle speed at this point. Put the car on the track and run it hard. You should have the HSN adjusted to the rich side of the max power band. Now when you bring the car into the pits it will probably be idling fast and after several seconds, will drop down in idle rpm. This is a sign that the LSN is still too rich. Lean it an hour at a time, and run another 2 laps hard. Repeat the process. Turn down the idle rpm until the idle speed is slow and steady after running hard and returning to the pits. Check your temp. Temp at idle should quickly drop below 200F and stabilize. Do the pinch test and confirm that the engine is still rich at idle. This works for me.
If I get confused, every thing goes back to too rich and start over again. When you first start out it really helps to keep notes.
Jack, that's exactly what I do !
