This doesn't make sense. You've tried speed pulls for 8 reps? Speed pulling consists of maybe 5 - 8 singles. Is that what you meant? Plus if your max is 220 kg, you may be better served to do speed pulls with 130 kg or less (and add accomadating resistance if available).
It sounds to me like speed pulls are exactly what you need. Increase rate of force production = getting the weight off the floor faster, and that's what speed pulls do.
Drop the weight and pull as fast as you can with 50 - 60% of your max for 5 - 8 singles and see if that helps.
Additionally, do you take your last breath in when you are standing or bent over? I ask because you can get some 'bounce' from your belly off your thighs to help you off the floor as you drop your hips down and sit back when you start to pull.