Technical RPM constant in drive

I'm not sure what to make of this one: The engine idles and builds RPM's as it should in park and neutral. I shift into drive, floor the gas pedal, and the RPM's change very little.

Car is a '56 Ford with a 292 and automatic. It is all stock. Any suggestions are appreciated.

 

When is the last time you changed your fuel filter?

 

when you post a question about something you should try to post your question so the answers will not be more questions.

all I can say is release the parking brake.

 

Fuel filter was replaced last week. Engine also has new spark plugs, points, condenser, and adjusted valves.

 

I don't mind answering questions if it gets me headed in the right direction. Sorry to have wasted 2 seconds of your Saturday with my original post.

 

If you floor the pedal and Rpms don't change nor does the engine stall I'd be looking first for a linkage issue to see that the throttle blades in the carb are opening. Next I'd be looking for a really bad air restriction some place.

 

Linkage looks to operating properly. The engine revs fine in park and neutral. RPM's just don't seem to build when in drive..

 

So lets get this straight, will the car move under it's own power in drive or not.
Your question is confusing as hell, no wonder you get more questions.

 

The car will move under its own power, but tops out around 30 mph.

 

Did you look down the carb throat and see the throttle blades move.

If one were to fully open the throttle on any engine running at 700 Rpms it will either accelerate or stall providing it has free air to grab. Is the air cleaner plugged?

 

Is the vacuum advance on the distributor working?

 

if your car was newer i would say it has a plugged catalytic converter . since your car doesn't have a cat i bet you have a rodent nest in you exhaust

 

I fought a 5 year old El Camino for a couple days one time that acted like that. Finally tracked it down to a muffler baffle that had rusted loose and blocked the outlet of the muffler. Unhook your exhaust and try it then. Might be as simple as a mashed pipe from banging a speed bump.

 

Did this just happen or did you get the car in this condition? Are the brakes dragging? Can you push the car easily?

 

Could you have a broken motor mount that lets the engine twist and jam the linkage?

 

I'd also check and make sure the exhaust wasn't stopped up...years ago when I first started racing I drove for one of the so called big engine and parts owners around...we broke a stock exhaust manifold one night...another racer went home and got us one...we put it on and went out..the car wouldn't run for nothing...it was rich and smutting the plugs on one side...the driver side was perfect...I left the engine to the smart guys cause it was their car and auto parts...their mechanic chased it 3 weeks and the 3rd night, for some dumb reason while leaning over the fender looking at the car in disgust...I reached down and grabbed the exhaust damper at the collector...it was froze up solid and only open about 1/2 inch when we pulled it off.........one of those simple things we never thought to look at...mechanic just knew we had messed something up in that head.......go figure....dumb blind luck

 

failed torque converter?

 

usually when a torque converter seizes up it acts like a manual transmission in high gear with the clutch engaged all the time. It will die when you drop it in gear and if you can keep it running it will act like it has no power. Then when you come to a stop it will kill the motor.