Idles fine but then no power....won't move.

[Ras12]

I am working on another recent DMC acquisition and replaced the fuel pump and return line. Also removed and cleaned all the injectors and went through the fuel distributor to make sure I was getting fresh fuel. I got her to idle ok and when cold the idle will hunt around then level out. I am sure I have a vacuum leak somewhere but will that prevent her from increasing the RPMs and moving while in gear because cannot move her when in gear. She just pops and farts when I give her gas. She won't stall out just cough and gag and not go anywhere.

I tried uploading a video but kept getting an error message.

Any input, advice or direction would be greatly appreciated.

[David T]

Do you hear the frequency valve buzzing?

[PJ Grady Inc.]

If the problem goes away after engine warmup I would check the Control Pressure Regutator and its vacuum source. Another possibility is a leak at the Idle Air Regulator particularly the air pipe to sensor housing connection.
Rob