1995 Ford Bronco

Hi, I have a 1995 Ford bronco with the 5.0l v8. It has been running pretty well until recently. I put in some fuel injector cleaner and since then the speedometer has been jumping at every speed, but worse the faster you go. When stopping the engine cuts out once in a while. It cuts out more often the harder you stop. The transmission is not shifting at the right points and it gets confused. For instance on a high way while cruising sometimes the transmission shifts and then shifts right back repeatedly and it feels like its gonna get ripped off. Then I change the throttle and it works fine. This all goes in and out though for instance as im driving sometimes everything goes back to normal or sometimes it goes from normal to everything I described. Thanks for any help.