My 89 gtu when it's cold and i step on the gas the check engine light comes on and it would like overload on fuel, but when it's all warm up still do it but less and everytime that do I have to turn it off and back on while running and the light will go away like for a half hour to. It's also running very rich and when is cold I have to go very slow until it warms up and I can go a little faster. I need heeelp. please?????