Boxer Idle Speed

While my injected car was in the shop for an alignment, I asked them to recheck my HC & CO since it seemed to be running rich. Turns out it was in the 3.0 range and was dropped to the proper 1.2-1.5. Now, my idle speed is abt 1200 hot, which I think is too high. What is the proper idle speed on a warm engine and can I adjust at the throttle stops in equal measure without messing up the vacuum and exhaust readings? Thanks

Ted,

You can carefully turn in the Large Air ByPass Screws to lower the idle (but you will need to plumb in 2 Manifold Vacum Gauges to get both Banks even) , but it will change the Mixture. How much is difficult to say. In very small increments the change could be minimal with no real ill side effects. Make sure the AC is off while making any adjustments, then check again with the AC on.

However, I would first check the Distributor Timing to make sure it didn't jump to a little to advanced and that it actually advances and returns to the correct 10 degrees before I touched the Air ByPass Screws. You might have slightly advanced timing and by correcting (if it's incorrect) can drop the idle speed with minimal affect to the A/F ratio.

Regards, JRV

Thanks JRV. Will check timing first. What is the proper idle speed on a warm engine anyway? Mine was at 800, now it is 1,200 to 1,400. Perhaps I am just being obsessive and should leave it alone?

When I tune a Boxer I set carb cars at 950-1000 and Injected cars at 1000-1050.

And the idle should settle back to spec fairly quickly when everything is set right.

Regards, JRV