Need help with leash pressure / engagement
So if you've been following the other threads where I've been spamming pics I have a 4 month old working line GSD puppy. In general training and simple obedience is going great. He learns quickly, has a food drive that is off the charts so luring and rewarding is easy, and it clearly engaged with me from start to finish. Sit, down, stand, recall, place, touch ... everything I have tried he has excelled at...
...except being anything less than 100% insane while on a leash. He has one speed--full speed ahead. He has one direction--the direction of whatever has caught his attention. I don't expect a puppy his age to have a perfect heel. However he is totally out of control on a leash and I know I need to get him going in the right direction (excuse the pun) before he gets older and bigger.
My biggest concern is his lack of engagement. When I am standing next to him with a leash attached I cease to exist. I know this is a failure on my part but I haven't been able to figure out what I'm doing wrong. I've tried a slip lead (not my first choice with a young puppy) and a martingale collar. I've tried sudden 90 degree turns when he starts to pull (which is immediately). I've tried the keep doing 180 degree turns even if you never make any progress technique. None of it seems to register with him in the slightest. It is our only interaction that is not positive and I'm trying really hard to come up with the right way to work with him on this. Like I said, I don't want a perfect heel at this stage. I just want to set him up for success as he gets older.
I will add that if I lure him with a high value treat (say hotdog) he will heel right along side me. As soon as the treats run out it is a full dash in a random direction until he slams into the end of the leash.
The last thing which concerns me is his frustration level. As I said, he tends to be oblivious to me while walking on a leash. That is until he can't get to whatever he is pulling towards for the 100th time, then he turns and tried to bite my pant leg at the knee. It isn't a full on bite, more of a puppy/shepherd nip at the jeans but I don't like the precedent it sets. Again, this only happens when leash walking.
I know this is handler error on my part. But every technique and trick I've ever been shown on how to teach respect and engagement while on a leash is failing miserably. Open to any and all suggestions. Thanks.