I got my project 4runner back today, I had the head redone due to burnt valves, and I reassembled, then took to mechanic to have him double check my work, set the valves and all that good stuff, well all that has been done and when i got it back to my shop it hesitates under 2000 rpm and once above that rpm it straightens right out, and the odd part is it even idles good, no check engine light and it is working, I dont understand, when i got it to the shop it hesitated through out the entire rpm band, and I figured it was the timing even though I was told it was check so I moved the distributor and it went to the current situation, and the distributor does not have any more room for adjustment, I am beginning to think that the chain is a tooth off, help me people