I own a 1985 Rx-7 and when I'm driving down the highway after i put on the break to slow down then when i try to return to original speed i loose power when i put down on the gas rpms do not rise or lower. Then when i put it in neutral and let the rpms decrease when i put it in gear again i have power. I've recently tuned it up new spark plugs, all new belts, new fuel filter etc. and the problem still exists