My 1987 4x4 Turbo Toyota truck has had a strange miss and luggish performance and a idle that cannot seem to make up its mind. Well I hope I am narrowing it down. When I pump the brake pedal my idle goes up say from 900rpm to 1200 rpm and stays at 1200 rpm if I continue to pump it. Could this be the problem of my poor performance, seems like my computer is getting bad signals from brake pedal? Mine seems to do the opposite of the brake pedal problem

I just disconnected brake fuse and it still has the problem? Any ideas thanks?

 

If your rpms are rising when you push the brake down that probably means you have a vacuum leak in your brake booster. About the poor performance at idle when was the last time you changed your plugs, fuel filter, and ran fuel injector cleaner through your truck?

 

I have done all of the above, maybe you are on to something, I will keep you posted.