Got1991 caddy press pedal to floor won't pickup speed engine dies out what's the problem could it be my fuel injectors fuel pump will not accelerate no leaks transmission good no smoke
1991 Cadillac STS 4.9 you need an engine no smoke coming out to tail pipes
From the lack of information in your post, the only thing I can surmise is your catalytic converter is plugged. With the age of your vehicle and the notice that it will not "pick up speed", this is the only thing which is coming to mind. Several things you can check.
If the engine idles just fine while the vehicle is in park, but when you rev it up, it will only get to say 2000-2500 rpm, then it sounds like it's just struggling to gain any more RPM, this could be the cat. Since you said the vehicle is not gaining speed no matter how hard you press the accelerator, this is another indication (basically the same thing, one is with a load, the other is not). Another thing to try is to wait until dark, then start the engine and let it idle until warm, then rev the engine as much as it will go, then have someone notice the exhaust manifolds. If while revving the engine they turn dull to cherry red, you are probably looking at the cat as well.
Even when plugged, the cat can still pass enough exhaust through it to allow the engine to run (most of the time). It just will not pass enough exhaust to allow it to run much higher than idle.
