While driving home the other night I tried to accelerate and around 3500 it felt like the engine shut off the came back on. It's not like a miss it just shuts off. The tach will drop all the way down to 500 the take back off and go back to 3000 then back down. No check engine lights my friend hooked it up to a tech 2 and everything shows normal. Hooked up fuel gauge and drove it and read 62 pounds when it was doing it. Thought it was the converter was plugged so I replaced it still no better. Any suggestions? It has 280,000 miles on it trans was rebuilt about 40,000 miles ago.