do you have at least 1 gallon of fuel through it? that's close to break in. also you are correct adjust low speed first. make sure your idle is set at .7mm-1mm then start with the lsn. also make sure car is warmed up at least 1 tank through it. also set the hsn back to flush then 1/2 turn in make sure you have a lot of smoke coming out when getting on the throttle. you will know when you are close to the sweet spot when you can idle for 10 seconds hit the gas and go.