ORIGINAL: Mr.Positive
Well i finally got my lst2 broken in and my LHS offers a free tune up if you bought the car there. So i took it in yesterday and got it tuned up. They had a line there so i left it there over night. The next day i picked it up and it seemed to run...mostly accelerate...poorly. My Question. Is the mach 427 supposed to happily run rich or could i lean out the low speed to keep it from dieing on idle and bogging from acceleration if i let it sit idling for a while?
It depends on several things. You can observe the engine by its sound, by its temp, and how it feels to the trigger. Since you feel it is sluggish, did it used to run much better? If so, they probably tuned it too rich. Also, listen to the sound of the engine, and if you have a temp gun, check the temp and run your engine between about 250-270degreesF. Listen to the sound of your engine. When your engine is at these temps and it responds great to the trigger, memorize the sounds it makes. This is the optimum tune. If you want to go slightly richer (most advise to runs slightly richer than max performance needle settings), then tuen about am 8th turn rich from best performance tune.
To me, I am guessing your engine is not yet fully broken in and your store tuned your engine a little too rich. How many tank have you put into that engine so far? It probaly is not yet fully broken in until you het about 8-10 tanks, depending on how precise the engine was made at the factory (particularly the piston & sleeve), the break-in method you chose, the oil content of your fuel, etc.